You are viewing a plain text version of this content. The canonical link for it is here.
Posted to user@hadoop.apache.org by "AMARNATH, Balachandar" <BA...@airbus.com> on 2013/03/06 10:51:07 UTC

Issue: Namenode is in safe mode

Hi,

I have created a hadoop cluster with two nodes (A and B). 'A' act both as namenode and datanode, and 'B' act as datanode only. With this setup, I could store, read files. Now, I added one more datanode 'C' and relieved 'A' from datanode duty. This means, 'A' act only as namenode, and both B and C act as datanodes. Now, I tried to create a directory, it says

' org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create directory Name node is in safe mode'


Can someone tell me why the namenode now is in safe mode?

With thanks and regards
Balachandar




The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.


RE: Issue: Namenode is in safe mode

Posted by Samir Kumar Das Mohapatra <da...@adobe.com>.
Just do it
$>  hadoop dfsadmin -safemode leave

From: AMARNATH, Balachandar [mailto:BALACHANDAR.AMARNATH@airbus.com]
Sent: 06 March 2013 15:21
To: user@hadoop.apache.org
Subject: Issue: Namenode is in safe mode


Hi,

I have created a hadoop cluster with two nodes (A and B). 'A' act both as namenode and datanode, and 'B' act as datanode only. With this setup, I could store, read files. Now, I added one more datanode 'C' and relieved 'A' from datanode duty. This means, 'A' act only as namenode, and both B and C act as datanodes. Now, I tried to create a directory, it says

' org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create directory Name node is in safe mode'


Can someone tell me why the namenode now is in safe mode?

With thanks and regards
Balachandar




The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.

If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.

Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.

All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.

RE: Issue: Namenode is in safe mode

Posted by Samir Kumar Das Mohapatra <da...@adobe.com>.
Just do it
$>  hadoop dfsadmin -safemode leave

From: AMARNATH, Balachandar [mailto:BALACHANDAR.AMARNATH@airbus.com]
Sent: 06 March 2013 15:21
To: user@hadoop.apache.org
Subject: Issue: Namenode is in safe mode


Hi,

I have created a hadoop cluster with two nodes (A and B). 'A' act both as namenode and datanode, and 'B' act as datanode only. With this setup, I could store, read files. Now, I added one more datanode 'C' and relieved 'A' from datanode duty. This means, 'A' act only as namenode, and both B and C act as datanodes. Now, I tried to create a directory, it says

' org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create directory Name node is in safe mode'


Can someone tell me why the namenode now is in safe mode?

With thanks and regards
Balachandar




The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.

If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.

Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.

All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.

Re: Issue: Namenode is in safe mode

Posted by Bertrand Dechoux <de...@gmail.com>.
How was the namenode A relieved of its duty and what was the default
replication factor?

If the replication factor was 1 and the datanode A was unplugged without
any care then you lost half of your files and your namenode is not really
happy about it (and is waiting for you to correct the mistake or let it
slip explicitely).

Regards

Bertrand

On Wed, Mar 6, 2013 at 10:51 AM, AMARNATH, Balachandar <
BALACHANDAR.AMARNATH@airbus.com> wrote:

>
> Hi,
>
> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
> could store, read files. Now, I added one more datanode ‘C’ and relieved
> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
> and C act as datanodes. Now, I tried to create a directory, it says
>
> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
> directory Name node is in safe mode’
>
>
> Can someone tell me why the namenode now is in safe mode?
>
> With thanks and regards
> Balachandar
>
>
>
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>
>

Re: Issue: Namenode is in safe mode

Posted by Bertrand Dechoux <de...@gmail.com>.
How was the namenode A relieved of its duty and what was the default
replication factor?

If the replication factor was 1 and the datanode A was unplugged without
any care then you lost half of your files and your namenode is not really
happy about it (and is waiting for you to correct the mistake or let it
slip explicitely).

Regards

Bertrand

On Wed, Mar 6, 2013 at 10:51 AM, AMARNATH, Balachandar <
BALACHANDAR.AMARNATH@airbus.com> wrote:

>
> Hi,
>
> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
> could store, read files. Now, I added one more datanode ‘C’ and relieved
> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
> and C act as datanodes. Now, I tried to create a directory, it says
>
> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
> directory Name node is in safe mode’
>
>
> Can someone tell me why the namenode now is in safe mode?
>
> With thanks and regards
> Balachandar
>
>
>
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>
>

Re: Issue: Namenode is in safe mode

Posted by Nitin Pawar <ni...@gmail.com>.
what is your replication factor?
when you removed node A as datanode .. did you first mark it for
retirement? if you just removed it from service then the blocks from that
datanode are missing and namenode when starts up it checks for the blocks.
Unless it reaches its threshold value it will not let you write any more
data on your hdfs.

I will suggest to start datanode on A, then mark it for retirement so
namenode will move the blocks to new datanode and once it is done namenode
will retire that datanode.




On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <
BALACHANDAR.AMARNATH@airbus.com> wrote:

>
> Hi,
>
> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
> could store, read files. Now, I added one more datanode ‘C’ and relieved
> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
> and C act as datanodes. Now, I tried to create a directory, it says
>
> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
> directory Name node is in safe mode’
>
>
> Can someone tell me why the namenode now is in safe mode?
>
> With thanks and regards
> Balachandar
>
>
>
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>
>


-- 
Nitin Pawar

RE: Issue: Namenode is in safe mode

Posted by Samir Kumar Das Mohapatra <da...@adobe.com>.
Just do it
$>  hadoop dfsadmin -safemode leave

From: AMARNATH, Balachandar [mailto:BALACHANDAR.AMARNATH@airbus.com]
Sent: 06 March 2013 15:21
To: user@hadoop.apache.org
Subject: Issue: Namenode is in safe mode


Hi,

I have created a hadoop cluster with two nodes (A and B). 'A' act both as namenode and datanode, and 'B' act as datanode only. With this setup, I could store, read files. Now, I added one more datanode 'C' and relieved 'A' from datanode duty. This means, 'A' act only as namenode, and both B and C act as datanodes. Now, I tried to create a directory, it says

' org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create directory Name node is in safe mode'


Can someone tell me why the namenode now is in safe mode?

With thanks and regards
Balachandar




The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.

If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.

Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.

All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.

Re: Issue: Namenode is in safe mode

Posted by Nitin Pawar <ni...@gmail.com>.
what is your replication factor?
when you removed node A as datanode .. did you first mark it for
retirement? if you just removed it from service then the blocks from that
datanode are missing and namenode when starts up it checks for the blocks.
Unless it reaches its threshold value it will not let you write any more
data on your hdfs.

I will suggest to start datanode on A, then mark it for retirement so
namenode will move the blocks to new datanode and once it is done namenode
will retire that datanode.




On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <
BALACHANDAR.AMARNATH@airbus.com> wrote:

>
> Hi,
>
> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
> could store, read files. Now, I added one more datanode ‘C’ and relieved
> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
> and C act as datanodes. Now, I tried to create a directory, it says
>
> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
> directory Name node is in safe mode’
>
>
> Can someone tell me why the namenode now is in safe mode?
>
> With thanks and regards
> Balachandar
>
>
>
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>
>


-- 
Nitin Pawar

Re: Issue: Namenode is in safe mode

Posted by Nitin Pawar <ni...@gmail.com>.
what is your replication factor?
when you removed node A as datanode .. did you first mark it for
retirement? if you just removed it from service then the blocks from that
datanode are missing and namenode when starts up it checks for the blocks.
Unless it reaches its threshold value it will not let you write any more
data on your hdfs.

I will suggest to start datanode on A, then mark it for retirement so
namenode will move the blocks to new datanode and once it is done namenode
will retire that datanode.




On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <
BALACHANDAR.AMARNATH@airbus.com> wrote:

>
> Hi,
>
> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
> could store, read files. Now, I added one more datanode ‘C’ and relieved
> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
> and C act as datanodes. Now, I tried to create a directory, it says
>
> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
> directory Name node is in safe mode’
>
>
> Can someone tell me why the namenode now is in safe mode?
>
> With thanks and regards
> Balachandar
>
>
>
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>
>


-- 
Nitin Pawar

Re: Issue: Namenode is in safe mode

Posted by Nitin Pawar <ni...@gmail.com>.
what is your replication factor?
when you removed node A as datanode .. did you first mark it for
retirement? if you just removed it from service then the blocks from that
datanode are missing and namenode when starts up it checks for the blocks.
Unless it reaches its threshold value it will not let you write any more
data on your hdfs.

I will suggest to start datanode on A, then mark it for retirement so
namenode will move the blocks to new datanode and once it is done namenode
will retire that datanode.




On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <
BALACHANDAR.AMARNATH@airbus.com> wrote:

>
> Hi,
>
> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
> could store, read files. Now, I added one more datanode ‘C’ and relieved
> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
> and C act as datanodes. Now, I tried to create a directory, it says
>
> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
> directory Name node is in safe mode’
>
>
> Can someone tell me why the namenode now is in safe mode?
>
> With thanks and regards
> Balachandar
>
>
>
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>
>


-- 
Nitin Pawar

Re: Issue: Namenode is in safe mode

Posted by Bertrand Dechoux <de...@gmail.com>.
How was the namenode A relieved of its duty and what was the default
replication factor?

If the replication factor was 1 and the datanode A was unplugged without
any care then you lost half of your files and your namenode is not really
happy about it (and is waiting for you to correct the mistake or let it
slip explicitely).

Regards

Bertrand

On Wed, Mar 6, 2013 at 10:51 AM, AMARNATH, Balachandar <
BALACHANDAR.AMARNATH@airbus.com> wrote:

>
> Hi,
>
> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
> could store, read files. Now, I added one more datanode ‘C’ and relieved
> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
> and C act as datanodes. Now, I tried to create a directory, it says
>
> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
> directory Name node is in safe mode’
>
>
> Can someone tell me why the namenode now is in safe mode?
>
> With thanks and regards
> Balachandar
>
>
>
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>
>

RE: Issue: Namenode is in safe mode

Posted by Samir Kumar Das Mohapatra <da...@adobe.com>.
Just do it
$>  hadoop dfsadmin -safemode leave

From: AMARNATH, Balachandar [mailto:BALACHANDAR.AMARNATH@airbus.com]
Sent: 06 March 2013 15:21
To: user@hadoop.apache.org
Subject: Issue: Namenode is in safe mode


Hi,

I have created a hadoop cluster with two nodes (A and B). 'A' act both as namenode and datanode, and 'B' act as datanode only. With this setup, I could store, read files. Now, I added one more datanode 'C' and relieved 'A' from datanode duty. This means, 'A' act only as namenode, and both B and C act as datanodes. Now, I tried to create a directory, it says

' org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create directory Name node is in safe mode'


Can someone tell me why the namenode now is in safe mode?

With thanks and regards
Balachandar




The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.

If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.

Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.

All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.

Re: Issue: Namenode is in safe mode

Posted by Bertrand Dechoux <de...@gmail.com>.
How was the namenode A relieved of its duty and what was the default
replication factor?

If the replication factor was 1 and the datanode A was unplugged without
any care then you lost half of your files and your namenode is not really
happy about it (and is waiting for you to correct the mistake or let it
slip explicitely).

Regards

Bertrand

On Wed, Mar 6, 2013 at 10:51 AM, AMARNATH, Balachandar <
BALACHANDAR.AMARNATH@airbus.com> wrote:

>
> Hi,
>
> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
> could store, read files. Now, I added one more datanode ‘C’ and relieved
> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
> and C act as datanodes. Now, I tried to create a directory, it says
>
> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
> directory Name node is in safe mode’
>
>
> Can someone tell me why the namenode now is in safe mode?
>
> With thanks and regards
> Balachandar
>
>
>
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>
>

Re: Issue: Namenode is in safe mode

Posted by shashwat shriparv <dw...@gmail.com>.
you can not directly remove a datanode from a cluster its not a proper way.
you need to decommission nodes and wait till the data from the datanode to
be removed are copied to other nodes.
just read document for proper decomissioning of nodes

http://helpmetocode.blogspot.in/2012/11/datanode-decommissioning-from-hadoop.html



∞
Shashwat Shriparv



On Wed, Mar 6, 2013 at 10:00 PM, Shumin Guo <gs...@gmail.com> wrote:

> To decommission a live datanode from the cluster, you can do the following
> steps:
>
> 1, edit configuration file $HADOOP_HOME/conf/hdfs-site.xml, and add the
> following property:
> <property>
> <name>dfs.hosts.exclude</name>
> <value>$HADOOP_HOME/conf/dfs-exclude.txt</value>
> </property>
>
> 2, put the host name of the node you want to decommission onto file
> $HADOOP_HOME/conf/dfs-exclude.xml (one host per line).
>
> 3, Run the following command:
> hadoop dfsadmin -refreshNodes
>
> Shumin
>
> On Wed, Mar 6, 2013 at 5:29 AM, AMARNATH, Balachandar <
> BALACHANDAR.AMARNATH@airbus.com> wrote:
>
>> The repliation factor was 1 when I removed the entry of A in slaves file.
>> I did not mark it retirement. I do not know yet how to mark a node for
>> retirement. I waited for few minutes and then I could see thte namenode
>> running again****
>>
>> ** **
>>
>> *From:* Nitin Pawar [mailto:nitinpawar432@gmail.com]
>> *Sent:* 06 March 2013 15:31
>> *To:* user@hadoop.apache.org
>> *Subject:* Re: Issue: Namenode is in safe mode****
>>
>> ** **
>>
>> what is your replication factor?****
>>
>> when you removed node A as datanode .. did you first mark it for
>> retirement? if you just removed it from service then the blocks from that
>> datanode are missing and namenode when starts up it checks for the blocks.
>> Unless it reaches its threshold value it will not let you write any more
>> data on your hdfs. ****
>>
>> ** **
>>
>> I will suggest to start datanode on A, then mark it for retirement so
>> namenode will move the blocks to new datanode and once it is done namenode
>> will retire that datanode. ****
>>
>> ** **
>>
>> ** **
>>
>> ** **
>>
>> On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <
>> BALACHANDAR.AMARNATH@airbus.com> wrote:****
>>
>>  ****
>>
>> Hi, ****
>>
>>  ****
>>
>> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
>> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
>> could store, read files. Now, I added one more datanode ‘C’ and relieved
>> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
>> and C act as datanodes. Now, I tried to create a directory, it says****
>>
>>  ****
>>
>> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
>> directory Name node is in safe mode’****
>>
>>  ****
>>
>>  ****
>>
>> Can someone tell me why the namenode now is in safe mode?****
>>
>>  ****
>>
>> With thanks and regards****
>>
>> Balachandar****
>>
>>  ****
>>
>>  ****
>>
>>  ****
>>
>> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.****
>>
>> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.****
>>
>> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.****
>>
>> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.****
>>
>>
>>
>> ****
>>
>> ** **
>>
>> --
>> Nitin Pawar****
>>
>> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
>> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
>> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
>> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>>
>>
>

Re: Issue: Namenode is in safe mode

Posted by shashwat shriparv <dw...@gmail.com>.
you can not directly remove a datanode from a cluster its not a proper way.
you need to decommission nodes and wait till the data from the datanode to
be removed are copied to other nodes.
just read document for proper decomissioning of nodes

http://helpmetocode.blogspot.in/2012/11/datanode-decommissioning-from-hadoop.html



∞
Shashwat Shriparv



On Wed, Mar 6, 2013 at 10:00 PM, Shumin Guo <gs...@gmail.com> wrote:

> To decommission a live datanode from the cluster, you can do the following
> steps:
>
> 1, edit configuration file $HADOOP_HOME/conf/hdfs-site.xml, and add the
> following property:
> <property>
> <name>dfs.hosts.exclude</name>
> <value>$HADOOP_HOME/conf/dfs-exclude.txt</value>
> </property>
>
> 2, put the host name of the node you want to decommission onto file
> $HADOOP_HOME/conf/dfs-exclude.xml (one host per line).
>
> 3, Run the following command:
> hadoop dfsadmin -refreshNodes
>
> Shumin
>
> On Wed, Mar 6, 2013 at 5:29 AM, AMARNATH, Balachandar <
> BALACHANDAR.AMARNATH@airbus.com> wrote:
>
>> The repliation factor was 1 when I removed the entry of A in slaves file.
>> I did not mark it retirement. I do not know yet how to mark a node for
>> retirement. I waited for few minutes and then I could see thte namenode
>> running again****
>>
>> ** **
>>
>> *From:* Nitin Pawar [mailto:nitinpawar432@gmail.com]
>> *Sent:* 06 March 2013 15:31
>> *To:* user@hadoop.apache.org
>> *Subject:* Re: Issue: Namenode is in safe mode****
>>
>> ** **
>>
>> what is your replication factor?****
>>
>> when you removed node A as datanode .. did you first mark it for
>> retirement? if you just removed it from service then the blocks from that
>> datanode are missing and namenode when starts up it checks for the blocks.
>> Unless it reaches its threshold value it will not let you write any more
>> data on your hdfs. ****
>>
>> ** **
>>
>> I will suggest to start datanode on A, then mark it for retirement so
>> namenode will move the blocks to new datanode and once it is done namenode
>> will retire that datanode. ****
>>
>> ** **
>>
>> ** **
>>
>> ** **
>>
>> On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <
>> BALACHANDAR.AMARNATH@airbus.com> wrote:****
>>
>>  ****
>>
>> Hi, ****
>>
>>  ****
>>
>> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
>> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
>> could store, read files. Now, I added one more datanode ‘C’ and relieved
>> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
>> and C act as datanodes. Now, I tried to create a directory, it says****
>>
>>  ****
>>
>> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
>> directory Name node is in safe mode’****
>>
>>  ****
>>
>>  ****
>>
>> Can someone tell me why the namenode now is in safe mode?****
>>
>>  ****
>>
>> With thanks and regards****
>>
>> Balachandar****
>>
>>  ****
>>
>>  ****
>>
>>  ****
>>
>> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.****
>>
>> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.****
>>
>> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.****
>>
>> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.****
>>
>>
>>
>> ****
>>
>> ** **
>>
>> --
>> Nitin Pawar****
>>
>> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
>> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
>> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
>> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>>
>>
>

Re: Issue: Namenode is in safe mode

Posted by shashwat shriparv <dw...@gmail.com>.
you can not directly remove a datanode from a cluster its not a proper way.
you need to decommission nodes and wait till the data from the datanode to
be removed are copied to other nodes.
just read document for proper decomissioning of nodes

http://helpmetocode.blogspot.in/2012/11/datanode-decommissioning-from-hadoop.html



∞
Shashwat Shriparv



On Wed, Mar 6, 2013 at 10:00 PM, Shumin Guo <gs...@gmail.com> wrote:

> To decommission a live datanode from the cluster, you can do the following
> steps:
>
> 1, edit configuration file $HADOOP_HOME/conf/hdfs-site.xml, and add the
> following property:
> <property>
> <name>dfs.hosts.exclude</name>
> <value>$HADOOP_HOME/conf/dfs-exclude.txt</value>
> </property>
>
> 2, put the host name of the node you want to decommission onto file
> $HADOOP_HOME/conf/dfs-exclude.xml (one host per line).
>
> 3, Run the following command:
> hadoop dfsadmin -refreshNodes
>
> Shumin
>
> On Wed, Mar 6, 2013 at 5:29 AM, AMARNATH, Balachandar <
> BALACHANDAR.AMARNATH@airbus.com> wrote:
>
>> The repliation factor was 1 when I removed the entry of A in slaves file.
>> I did not mark it retirement. I do not know yet how to mark a node for
>> retirement. I waited for few minutes and then I could see thte namenode
>> running again****
>>
>> ** **
>>
>> *From:* Nitin Pawar [mailto:nitinpawar432@gmail.com]
>> *Sent:* 06 March 2013 15:31
>> *To:* user@hadoop.apache.org
>> *Subject:* Re: Issue: Namenode is in safe mode****
>>
>> ** **
>>
>> what is your replication factor?****
>>
>> when you removed node A as datanode .. did you first mark it for
>> retirement? if you just removed it from service then the blocks from that
>> datanode are missing and namenode when starts up it checks for the blocks.
>> Unless it reaches its threshold value it will not let you write any more
>> data on your hdfs. ****
>>
>> ** **
>>
>> I will suggest to start datanode on A, then mark it for retirement so
>> namenode will move the blocks to new datanode and once it is done namenode
>> will retire that datanode. ****
>>
>> ** **
>>
>> ** **
>>
>> ** **
>>
>> On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <
>> BALACHANDAR.AMARNATH@airbus.com> wrote:****
>>
>>  ****
>>
>> Hi, ****
>>
>>  ****
>>
>> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
>> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
>> could store, read files. Now, I added one more datanode ‘C’ and relieved
>> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
>> and C act as datanodes. Now, I tried to create a directory, it says****
>>
>>  ****
>>
>> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
>> directory Name node is in safe mode’****
>>
>>  ****
>>
>>  ****
>>
>> Can someone tell me why the namenode now is in safe mode?****
>>
>>  ****
>>
>> With thanks and regards****
>>
>> Balachandar****
>>
>>  ****
>>
>>  ****
>>
>>  ****
>>
>> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.****
>>
>> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.****
>>
>> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.****
>>
>> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.****
>>
>>
>>
>> ****
>>
>> ** **
>>
>> --
>> Nitin Pawar****
>>
>> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
>> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
>> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
>> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>>
>>
>

Re: Issue: Namenode is in safe mode

Posted by shashwat shriparv <dw...@gmail.com>.
you can not directly remove a datanode from a cluster its not a proper way.
you need to decommission nodes and wait till the data from the datanode to
be removed are copied to other nodes.
just read document for proper decomissioning of nodes

http://helpmetocode.blogspot.in/2012/11/datanode-decommissioning-from-hadoop.html



∞
Shashwat Shriparv



On Wed, Mar 6, 2013 at 10:00 PM, Shumin Guo <gs...@gmail.com> wrote:

> To decommission a live datanode from the cluster, you can do the following
> steps:
>
> 1, edit configuration file $HADOOP_HOME/conf/hdfs-site.xml, and add the
> following property:
> <property>
> <name>dfs.hosts.exclude</name>
> <value>$HADOOP_HOME/conf/dfs-exclude.txt</value>
> </property>
>
> 2, put the host name of the node you want to decommission onto file
> $HADOOP_HOME/conf/dfs-exclude.xml (one host per line).
>
> 3, Run the following command:
> hadoop dfsadmin -refreshNodes
>
> Shumin
>
> On Wed, Mar 6, 2013 at 5:29 AM, AMARNATH, Balachandar <
> BALACHANDAR.AMARNATH@airbus.com> wrote:
>
>> The repliation factor was 1 when I removed the entry of A in slaves file.
>> I did not mark it retirement. I do not know yet how to mark a node for
>> retirement. I waited for few minutes and then I could see thte namenode
>> running again****
>>
>> ** **
>>
>> *From:* Nitin Pawar [mailto:nitinpawar432@gmail.com]
>> *Sent:* 06 March 2013 15:31
>> *To:* user@hadoop.apache.org
>> *Subject:* Re: Issue: Namenode is in safe mode****
>>
>> ** **
>>
>> what is your replication factor?****
>>
>> when you removed node A as datanode .. did you first mark it for
>> retirement? if you just removed it from service then the blocks from that
>> datanode are missing and namenode when starts up it checks for the blocks.
>> Unless it reaches its threshold value it will not let you write any more
>> data on your hdfs. ****
>>
>> ** **
>>
>> I will suggest to start datanode on A, then mark it for retirement so
>> namenode will move the blocks to new datanode and once it is done namenode
>> will retire that datanode. ****
>>
>> ** **
>>
>> ** **
>>
>> ** **
>>
>> On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <
>> BALACHANDAR.AMARNATH@airbus.com> wrote:****
>>
>>  ****
>>
>> Hi, ****
>>
>>  ****
>>
>> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
>> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
>> could store, read files. Now, I added one more datanode ‘C’ and relieved
>> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
>> and C act as datanodes. Now, I tried to create a directory, it says****
>>
>>  ****
>>
>> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
>> directory Name node is in safe mode’****
>>
>>  ****
>>
>>  ****
>>
>> Can someone tell me why the namenode now is in safe mode?****
>>
>>  ****
>>
>> With thanks and regards****
>>
>> Balachandar****
>>
>>  ****
>>
>>  ****
>>
>>  ****
>>
>> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.****
>>
>> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.****
>>
>> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.****
>>
>> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.****
>>
>>
>>
>> ****
>>
>> ** **
>>
>> --
>> Nitin Pawar****
>>
>> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
>> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
>> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
>> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>>
>>
>

Re: Issue: Namenode is in safe mode

Posted by Shumin Guo <gs...@gmail.com>.
To decommission a live datanode from the cluster, you can do the following
steps:

1, edit configuration file $HADOOP_HOME/conf/hdfs-site.xml, and add the
following property:
<property>
<name>dfs.hosts.exclude</name>
<value>$HADOOP_HOME/conf/dfs-exclude.txt</value>
</property>

2, put the host name of the node you want to decommission onto file
$HADOOP_HOME/conf/dfs-exclude.xml (one host per line).

3, Run the following command:
hadoop dfsadmin -refreshNodes

Shumin

On Wed, Mar 6, 2013 at 5:29 AM, AMARNATH, Balachandar <
BALACHANDAR.AMARNATH@airbus.com> wrote:

> The repliation factor was 1 when I removed the entry of A in slaves file.
> I did not mark it retirement. I do not know yet how to mark a node for
> retirement. I waited for few minutes and then I could see thte namenode
> running again****
>
> ** **
>
> *From:* Nitin Pawar [mailto:nitinpawar432@gmail.com]
> *Sent:* 06 March 2013 15:31
> *To:* user@hadoop.apache.org
> *Subject:* Re: Issue: Namenode is in safe mode****
>
> ** **
>
> what is your replication factor?****
>
> when you removed node A as datanode .. did you first mark it for
> retirement? if you just removed it from service then the blocks from that
> datanode are missing and namenode when starts up it checks for the blocks.
> Unless it reaches its threshold value it will not let you write any more
> data on your hdfs. ****
>
> ** **
>
> I will suggest to start datanode on A, then mark it for retirement so
> namenode will move the blocks to new datanode and once it is done namenode
> will retire that datanode. ****
>
> ** **
>
> ** **
>
> ** **
>
> On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <
> BALACHANDAR.AMARNATH@airbus.com> wrote:****
>
>  ****
>
> Hi, ****
>
>  ****
>
> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
> could store, read files. Now, I added one more datanode ‘C’ and relieved
> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
> and C act as datanodes. Now, I tried to create a directory, it says****
>
>  ****
>
> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
> directory Name node is in safe mode’****
>
>  ****
>
>  ****
>
> Can someone tell me why the namenode now is in safe mode?****
>
>  ****
>
> With thanks and regards****
>
> Balachandar****
>
>  ****
>
>  ****
>
>  ****
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.****
>
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.****
>
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.****
>
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.****
>
>
>
> ****
>
> ** **
>
> --
> Nitin Pawar****
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>
>

Re: Issue: Namenode is in safe mode

Posted by Shumin Guo <gs...@gmail.com>.
To decommission a live datanode from the cluster, you can do the following
steps:

1, edit configuration file $HADOOP_HOME/conf/hdfs-site.xml, and add the
following property:
<property>
<name>dfs.hosts.exclude</name>
<value>$HADOOP_HOME/conf/dfs-exclude.txt</value>
</property>

2, put the host name of the node you want to decommission onto file
$HADOOP_HOME/conf/dfs-exclude.xml (one host per line).

3, Run the following command:
hadoop dfsadmin -refreshNodes

Shumin

On Wed, Mar 6, 2013 at 5:29 AM, AMARNATH, Balachandar <
BALACHANDAR.AMARNATH@airbus.com> wrote:

> The repliation factor was 1 when I removed the entry of A in slaves file.
> I did not mark it retirement. I do not know yet how to mark a node for
> retirement. I waited for few minutes and then I could see thte namenode
> running again****
>
> ** **
>
> *From:* Nitin Pawar [mailto:nitinpawar432@gmail.com]
> *Sent:* 06 March 2013 15:31
> *To:* user@hadoop.apache.org
> *Subject:* Re: Issue: Namenode is in safe mode****
>
> ** **
>
> what is your replication factor?****
>
> when you removed node A as datanode .. did you first mark it for
> retirement? if you just removed it from service then the blocks from that
> datanode are missing and namenode when starts up it checks for the blocks.
> Unless it reaches its threshold value it will not let you write any more
> data on your hdfs. ****
>
> ** **
>
> I will suggest to start datanode on A, then mark it for retirement so
> namenode will move the blocks to new datanode and once it is done namenode
> will retire that datanode. ****
>
> ** **
>
> ** **
>
> ** **
>
> On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <
> BALACHANDAR.AMARNATH@airbus.com> wrote:****
>
>  ****
>
> Hi, ****
>
>  ****
>
> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
> could store, read files. Now, I added one more datanode ‘C’ and relieved
> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
> and C act as datanodes. Now, I tried to create a directory, it says****
>
>  ****
>
> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
> directory Name node is in safe mode’****
>
>  ****
>
>  ****
>
> Can someone tell me why the namenode now is in safe mode?****
>
>  ****
>
> With thanks and regards****
>
> Balachandar****
>
>  ****
>
>  ****
>
>  ****
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.****
>
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.****
>
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.****
>
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.****
>
>
>
> ****
>
> ** **
>
> --
> Nitin Pawar****
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>
>

Re: Issue: Namenode is in safe mode

Posted by Shumin Guo <gs...@gmail.com>.
To decommission a live datanode from the cluster, you can do the following
steps:

1, edit configuration file $HADOOP_HOME/conf/hdfs-site.xml, and add the
following property:
<property>
<name>dfs.hosts.exclude</name>
<value>$HADOOP_HOME/conf/dfs-exclude.txt</value>
</property>

2, put the host name of the node you want to decommission onto file
$HADOOP_HOME/conf/dfs-exclude.xml (one host per line).

3, Run the following command:
hadoop dfsadmin -refreshNodes

Shumin

On Wed, Mar 6, 2013 at 5:29 AM, AMARNATH, Balachandar <
BALACHANDAR.AMARNATH@airbus.com> wrote:

> The repliation factor was 1 when I removed the entry of A in slaves file.
> I did not mark it retirement. I do not know yet how to mark a node for
> retirement. I waited for few minutes and then I could see thte namenode
> running again****
>
> ** **
>
> *From:* Nitin Pawar [mailto:nitinpawar432@gmail.com]
> *Sent:* 06 March 2013 15:31
> *To:* user@hadoop.apache.org
> *Subject:* Re: Issue: Namenode is in safe mode****
>
> ** **
>
> what is your replication factor?****
>
> when you removed node A as datanode .. did you first mark it for
> retirement? if you just removed it from service then the blocks from that
> datanode are missing and namenode when starts up it checks for the blocks.
> Unless it reaches its threshold value it will not let you write any more
> data on your hdfs. ****
>
> ** **
>
> I will suggest to start datanode on A, then mark it for retirement so
> namenode will move the blocks to new datanode and once it is done namenode
> will retire that datanode. ****
>
> ** **
>
> ** **
>
> ** **
>
> On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <
> BALACHANDAR.AMARNATH@airbus.com> wrote:****
>
>  ****
>
> Hi, ****
>
>  ****
>
> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
> could store, read files. Now, I added one more datanode ‘C’ and relieved
> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
> and C act as datanodes. Now, I tried to create a directory, it says****
>
>  ****
>
> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
> directory Name node is in safe mode’****
>
>  ****
>
>  ****
>
> Can someone tell me why the namenode now is in safe mode?****
>
>  ****
>
> With thanks and regards****
>
> Balachandar****
>
>  ****
>
>  ****
>
>  ****
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.****
>
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.****
>
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.****
>
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.****
>
>
>
> ****
>
> ** **
>
> --
> Nitin Pawar****
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>
>

Re: Issue: Namenode is in safe mode

Posted by Shumin Guo <gs...@gmail.com>.
To decommission a live datanode from the cluster, you can do the following
steps:

1, edit configuration file $HADOOP_HOME/conf/hdfs-site.xml, and add the
following property:
<property>
<name>dfs.hosts.exclude</name>
<value>$HADOOP_HOME/conf/dfs-exclude.txt</value>
</property>

2, put the host name of the node you want to decommission onto file
$HADOOP_HOME/conf/dfs-exclude.xml (one host per line).

3, Run the following command:
hadoop dfsadmin -refreshNodes

Shumin

On Wed, Mar 6, 2013 at 5:29 AM, AMARNATH, Balachandar <
BALACHANDAR.AMARNATH@airbus.com> wrote:

> The repliation factor was 1 when I removed the entry of A in slaves file.
> I did not mark it retirement. I do not know yet how to mark a node for
> retirement. I waited for few minutes and then I could see thte namenode
> running again****
>
> ** **
>
> *From:* Nitin Pawar [mailto:nitinpawar432@gmail.com]
> *Sent:* 06 March 2013 15:31
> *To:* user@hadoop.apache.org
> *Subject:* Re: Issue: Namenode is in safe mode****
>
> ** **
>
> what is your replication factor?****
>
> when you removed node A as datanode .. did you first mark it for
> retirement? if you just removed it from service then the blocks from that
> datanode are missing and namenode when starts up it checks for the blocks.
> Unless it reaches its threshold value it will not let you write any more
> data on your hdfs. ****
>
> ** **
>
> I will suggest to start datanode on A, then mark it for retirement so
> namenode will move the blocks to new datanode and once it is done namenode
> will retire that datanode. ****
>
> ** **
>
> ** **
>
> ** **
>
> On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <
> BALACHANDAR.AMARNATH@airbus.com> wrote:****
>
>  ****
>
> Hi, ****
>
>  ****
>
> I have created a hadoop cluster with two nodes (A and B). ‘A’ act both as
> namenode and datanode, and ‘B’ act as datanode only. With this setup, I
> could store, read files. Now, I added one more datanode ‘C’ and relieved
> ‘A’ from datanode duty. This means, ‘A’ act only as namenode, and both B
> and C act as datanodes. Now, I tried to create a directory, it says****
>
>  ****
>
> ‘ org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create
> directory Name node is in safe mode’****
>
>  ****
>
>  ****
>
> Can someone tell me why the namenode now is in safe mode?****
>
>  ****
>
> With thanks and regards****
>
> Balachandar****
>
>  ****
>
>  ****
>
>  ****
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.****
>
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.****
>
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.****
>
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.****
>
>
>
> ****
>
> ** **
>
> --
> Nitin Pawar****
>
> The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
> If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
> Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
> All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.
>
>

RE: Issue: Namenode is in safe mode

Posted by "AMARNATH, Balachandar" <BA...@airbus.com>.
The repliation factor was 1 when I removed the entry of A in slaves file. I did not mark it retirement. I do not know yet how to mark a node for retirement. I waited for few minutes and then I could see thte namenode running again

From: Nitin Pawar [mailto:nitinpawar432@gmail.com]
Sent: 06 March 2013 15:31
To: user@hadoop.apache.org
Subject: Re: Issue: Namenode is in safe mode

what is your replication factor?
when you removed node A as datanode .. did you first mark it for retirement? if you just removed it from service then the blocks from that datanode are missing and namenode when starts up it checks for the blocks. Unless it reaches its threshold value it will not let you write any more data on your hdfs.

I will suggest to start datanode on A, then mark it for retirement so namenode will move the blocks to new datanode and once it is done namenode will retire that datanode.



On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <BA...@airbus.com>> wrote:

Hi,

I have created a hadoop cluster with two nodes (A and B). 'A' act both as namenode and datanode, and 'B' act as datanode only. With this setup, I could store, read files. Now, I added one more datanode 'C' and relieved 'A' from datanode duty. This means, 'A' act only as namenode, and both B and C act as datanodes. Now, I tried to create a directory, it says

' org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create directory Name node is in safe mode'


Can someone tell me why the namenode now is in safe mode?

With thanks and regards
Balachandar




The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.

If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.

Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.

All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.



--
Nitin Pawar

The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.


RE: Issue: Namenode is in safe mode

Posted by "AMARNATH, Balachandar" <BA...@airbus.com>.
The repliation factor was 1 when I removed the entry of A in slaves file. I did not mark it retirement. I do not know yet how to mark a node for retirement. I waited for few minutes and then I could see thte namenode running again

From: Nitin Pawar [mailto:nitinpawar432@gmail.com]
Sent: 06 March 2013 15:31
To: user@hadoop.apache.org
Subject: Re: Issue: Namenode is in safe mode

what is your replication factor?
when you removed node A as datanode .. did you first mark it for retirement? if you just removed it from service then the blocks from that datanode are missing and namenode when starts up it checks for the blocks. Unless it reaches its threshold value it will not let you write any more data on your hdfs.

I will suggest to start datanode on A, then mark it for retirement so namenode will move the blocks to new datanode and once it is done namenode will retire that datanode.



On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <BA...@airbus.com>> wrote:

Hi,

I have created a hadoop cluster with two nodes (A and B). 'A' act both as namenode and datanode, and 'B' act as datanode only. With this setup, I could store, read files. Now, I added one more datanode 'C' and relieved 'A' from datanode duty. This means, 'A' act only as namenode, and both B and C act as datanodes. Now, I tried to create a directory, it says

' org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create directory Name node is in safe mode'


Can someone tell me why the namenode now is in safe mode?

With thanks and regards
Balachandar




The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.

If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.

Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.

All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.



--
Nitin Pawar

The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.


RE: Issue: Namenode is in safe mode

Posted by "AMARNATH, Balachandar" <BA...@airbus.com>.
The repliation factor was 1 when I removed the entry of A in slaves file. I did not mark it retirement. I do not know yet how to mark a node for retirement. I waited for few minutes and then I could see thte namenode running again

From: Nitin Pawar [mailto:nitinpawar432@gmail.com]
Sent: 06 March 2013 15:31
To: user@hadoop.apache.org
Subject: Re: Issue: Namenode is in safe mode

what is your replication factor?
when you removed node A as datanode .. did you first mark it for retirement? if you just removed it from service then the blocks from that datanode are missing and namenode when starts up it checks for the blocks. Unless it reaches its threshold value it will not let you write any more data on your hdfs.

I will suggest to start datanode on A, then mark it for retirement so namenode will move the blocks to new datanode and once it is done namenode will retire that datanode.



On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <BA...@airbus.com>> wrote:

Hi,

I have created a hadoop cluster with two nodes (A and B). 'A' act both as namenode and datanode, and 'B' act as datanode only. With this setup, I could store, read files. Now, I added one more datanode 'C' and relieved 'A' from datanode duty. This means, 'A' act only as namenode, and both B and C act as datanodes. Now, I tried to create a directory, it says

' org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create directory Name node is in safe mode'


Can someone tell me why the namenode now is in safe mode?

With thanks and regards
Balachandar




The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.

If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.

Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.

All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.



--
Nitin Pawar

The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.


RE: Issue: Namenode is in safe mode

Posted by "AMARNATH, Balachandar" <BA...@airbus.com>.
The repliation factor was 1 when I removed the entry of A in slaves file. I did not mark it retirement. I do not know yet how to mark a node for retirement. I waited for few minutes and then I could see thte namenode running again

From: Nitin Pawar [mailto:nitinpawar432@gmail.com]
Sent: 06 March 2013 15:31
To: user@hadoop.apache.org
Subject: Re: Issue: Namenode is in safe mode

what is your replication factor?
when you removed node A as datanode .. did you first mark it for retirement? if you just removed it from service then the blocks from that datanode are missing and namenode when starts up it checks for the blocks. Unless it reaches its threshold value it will not let you write any more data on your hdfs.

I will suggest to start datanode on A, then mark it for retirement so namenode will move the blocks to new datanode and once it is done namenode will retire that datanode.



On Wed, Mar 6, 2013 at 3:21 PM, AMARNATH, Balachandar <BA...@airbus.com>> wrote:

Hi,

I have created a hadoop cluster with two nodes (A and B). 'A' act both as namenode and datanode, and 'B' act as datanode only. With this setup, I could store, read files. Now, I added one more datanode 'C' and relieved 'A' from datanode duty. This means, 'A' act only as namenode, and both B and C act as datanodes. Now, I tried to create a directory, it says

' org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create directory Name node is in safe mode'


Can someone tell me why the namenode now is in safe mode?

With thanks and regards
Balachandar




The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.

If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.

Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.

All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.



--
Nitin Pawar

The information in this e-mail is confidential. The contents may not be disclosed or used by anyone other than the addressee. Access to this e-mail by anyone else is unauthorised.
If you are not the intended recipient, please notify Airbus immediately and delete this e-mail.
Airbus cannot accept any responsibility for the accuracy or completeness of this e-mail as it has been sent over public networks. If you have any concerns over the content of this message or its Accuracy or Integrity, please contact Airbus immediately.
All outgoing e-mails from Airbus are checked using regularly updated virus scanning software but you should take whatever measures you deem to be appropriate to ensure that this message and any attachments are virus free.