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Posted to users@cloudstack.apache.org by France <ma...@isg.si> on 2015/06/21 12:43:10 UTC
Access root disk after botched upgrade
Hi,
after upgrading Ubuntu Linux, the system does not boot, probably because of wrong grub config format:
( errorInfo: [Traceback (most recent call last):, File "/usr/bin/pygrub", line 808, in ?, fs = fsimage.open(file, part_offs[0], bootfsoptions), IndexError: list index out of range, ])
How can I get access to disk of this VM, to fix the grub file by hand and try to restart it?
I have CS 4.3 on XS 6.0.2 with ISCSI disk for virtual instances.
Tnx.
France.
Re: Access root disk after botched upgrade
Posted by ilya <il...@gmail.com>.
For KVM i'm not certain, for VMware - you can pass arbitrary vmware
specific configs via API, assume one can pass boot order - but havent
yet tried..
Regards,
On 6/24/15 8:56 AM, Nux! wrote:
> France,
>
> I am not sure changing the boot sequence can be changed. In KVM installations if an ISO is attached then it will be booted automatically, I assume it's the same with Xenserver.
>
> --
> Sent from the Delta quadrant using Borg technology!
>
> Nux!
> www.nux.ro
>
> ----- Original Message -----
>> From: "France" <ma...@isg.si>
>> To: users@cloudstack.apache.org
>> Sent: Wednesday, 24 June, 2015 14:19:15
>> Subject: Re: Access root disk after botched upgrade
>> Just for the future reference, how can I change the boot order to boot from CD
>> first?
>>
>> I shut down one of the working instances and attached the iso for centos 6.4
>> minimal to it. Started the instance again and it did boot form disk as
>> expected. I also did not see an option to boot from cd on console.
>>
>> Tnx and regards,
>> F.
>>
>> On 22 Jun 2015, at 18:56, Nux! <nu...@li.nux.ro> wrote:
>>
>>> Add a Livecd ISO, attach it to the instance and boot from it?
>>>
>>> --
>>> Sent from the Delta quadrant using Borg technology!
>>>
>>> Nux!
>>> www.nux.ro
>>>
>>> ----- Original Message -----
>>>> From: "France" <ma...@isg.si>
>>>> To: users@cloudstack.apache.org
>>>> Sent: Sunday, 21 June, 2015 11:43:10
>>>> Subject: Access root disk after botched upgrade
>>>> Hi,
>>>>
>>>> after upgrading Ubuntu Linux, the system does not boot, probably because of
>>>> wrong grub config format:
>>>> ( errorInfo: [Traceback (most recent call last):, File
>>>> "/usr/bin/pygrub", line 808, in ?, fs = fsimage.open(file, part_offs[0],
>>>> bootfsoptions), IndexError: list index out of range, ])
>>>>
>>>> How can I get access to disk of this VM, to fix the grub file by hand and try to
>>>> restart it?
>>>> I have CS 4.3 on XS 6.0.2 with ISCSI disk for virtual instances.
>>>>
>>>> Tnx.
>>>> France.
Re: Access root disk after botched upgrade
Posted by Nux! <nu...@li.nux.ro>.
France,
I am not sure changing the boot sequence can be changed. In KVM installations if an ISO is attached then it will be booted automatically, I assume it's the same with Xenserver.
--
Sent from the Delta quadrant using Borg technology!
Nux!
www.nux.ro
----- Original Message -----
> From: "France" <ma...@isg.si>
> To: users@cloudstack.apache.org
> Sent: Wednesday, 24 June, 2015 14:19:15
> Subject: Re: Access root disk after botched upgrade
> Just for the future reference, how can I change the boot order to boot from CD
> first?
>
> I shut down one of the working instances and attached the iso for centos 6.4
> minimal to it. Started the instance again and it did boot form disk as
> expected. I also did not see an option to boot from cd on console.
>
> Tnx and regards,
> F.
>
> On 22 Jun 2015, at 18:56, Nux! <nu...@li.nux.ro> wrote:
>
>> Add a Livecd ISO, attach it to the instance and boot from it?
>>
>> --
>> Sent from the Delta quadrant using Borg technology!
>>
>> Nux!
>> www.nux.ro
>>
>> ----- Original Message -----
>>> From: "France" <ma...@isg.si>
>>> To: users@cloudstack.apache.org
>>> Sent: Sunday, 21 June, 2015 11:43:10
>>> Subject: Access root disk after botched upgrade
>>
>>> Hi,
>>>
>>> after upgrading Ubuntu Linux, the system does not boot, probably because of
>>> wrong grub config format:
>>> ( errorInfo: [Traceback (most recent call last):, File
>>> "/usr/bin/pygrub", line 808, in ?, fs = fsimage.open(file, part_offs[0],
>>> bootfsoptions), IndexError: list index out of range, ])
>>>
>>> How can I get access to disk of this VM, to fix the grub file by hand and try to
>>> restart it?
>>> I have CS 4.3 on XS 6.0.2 with ISCSI disk for virtual instances.
>>>
>>> Tnx.
> >> France.
Re: Access root disk after botched upgrade
Posted by France <ma...@isg.si>.
Just for the future reference, how can I change the boot order to boot from CD first?
I shut down one of the working instances and attached the iso for centos 6.4 minimal to it. Started the instance again and it did boot form disk as expected. I also did not see an option to boot from cd on console.
Tnx and regards,
F.
On 22 Jun 2015, at 18:56, Nux! <nu...@li.nux.ro> wrote:
> Add a Livecd ISO, attach it to the instance and boot from it?
>
> --
> Sent from the Delta quadrant using Borg technology!
>
> Nux!
> www.nux.ro
>
> ----- Original Message -----
>> From: "France" <ma...@isg.si>
>> To: users@cloudstack.apache.org
>> Sent: Sunday, 21 June, 2015 11:43:10
>> Subject: Access root disk after botched upgrade
>
>> Hi,
>>
>> after upgrading Ubuntu Linux, the system does not boot, probably because of
>> wrong grub config format:
>> ( errorInfo: [Traceback (most recent call last):, File
>> "/usr/bin/pygrub", line 808, in ?, fs = fsimage.open(file, part_offs[0],
>> bootfsoptions), IndexError: list index out of range, ])
>>
>> How can I get access to disk of this VM, to fix the grub file by hand and try to
>> restart it?
>> I have CS 4.3 on XS 6.0.2 with ISCSI disk for virtual instances.
>>
>> Tnx.
>> France.
Re: Access root disk after botched upgrade
Posted by Nux! <nu...@li.nux.ro>.
Add a Livecd ISO, attach it to the instance and boot from it?
--
Sent from the Delta quadrant using Borg technology!
Nux!
www.nux.ro
----- Original Message -----
> From: "France" <ma...@isg.si>
> To: users@cloudstack.apache.org
> Sent: Sunday, 21 June, 2015 11:43:10
> Subject: Access root disk after botched upgrade
> Hi,
>
> after upgrading Ubuntu Linux, the system does not boot, probably because of
> wrong grub config format:
> ( errorInfo: [Traceback (most recent call last):, File
> "/usr/bin/pygrub", line 808, in ?, fs = fsimage.open(file, part_offs[0],
> bootfsoptions), IndexError: list index out of range, ])
>
> How can I get access to disk of this VM, to fix the grub file by hand and try to
> restart it?
> I have CS 4.3 on XS 6.0.2 with ISCSI disk for virtual instances.
>
> Tnx.
> France.
Re: Access root disk after botched upgrade
Posted by France <ma...@isg.si>.
Hi guys.
Thank you both for your suggestion.
I did not know one can attach root disk from offline instance to another running instance using CS.
If I were to choose, i would go with the XenCenter method, because I really do not feel comfortable with playing on live clustered LVM over ISCSI setup.
Actually it turned out, that it was easier just rolling a new instance and import data from offsite backup.
The owner installed grub to /dev/xvda, where filesystem resides (no partitions). I guess it could be fixed, but one would have to fsck FS first.
Tnx again and Regards,
F.
On 21 Jun 2015, at 16:49, Tim Mackey <tm...@gmail.com> wrote:
> If that process didn't work, here's another (using XenCenter)
>
> 1. Stop the original VM (the one you want to fix). Note it's VM name and
> find it in your XenServer resource pool.
> 2. Create a new VM within CS and start it. Note the VM name and find it
> within your XenServer resource pool
> 3. On the original VM, give the root disk a readily identifiable
> description (it'll help in this process)
> 4. Detach the root disk from the original VM
> 5. Find the original root disk and attach it to your second VM and note the
> device id assigned to it
> 6. Login to the second VM and mount the original root disk
> 7. Fix grub
> 8. Unmount the original root disk
> 9. Detach original root disk from the second VM
> 10. Reattach the original root disk to the original VM
> 11. Start the original VM.
>
> At this point everything should be working (provided grub was the issue).
>
> While I've given the process using XenCenter, it can be done with CLI.
> It's just a bit harder to keep track of the correct uuids using the CLI.
> Note that in all of this, if you need to move VMs from one host to another,
> that's fine, just make certain they are back on their original hosts when
> you're done lest CS get confused.
>
> -tim
>
> On Sun, Jun 21, 2015 at 7:14 AM, Stephan Seitz <
> s.seitz@secretresearchfacility.com> wrote:
>
>> Hi,
>>
>> on XenServer I'ld expect your SR containing *.vhd files. You could use
>> the cli "xe" command to determine which file is attached. Maybe this
>> info can also be seen in the gui.
>>
>> Here's a short walkthrough, how to access vhd files:
>> http://wiki.xen.org/wiki/Mounting_a_.vhd_disk_image_using_blktap/tapdisk
>>
>> If your vhd file contains partitions, you could do a
>> kpartx -a /dev/xen/....
>> to get
>> /dev/mapper/blktap0p[0....n]
>>
>> Depending on your guest OS, e.g. If there's LVM or dm-crypt etc...
>> inside the following steps vary.
>>
>> Just use standard linux tools to mount / pvscan / cryptsetup / ...
>> the /dev/mapper/blktap... partitions.
>>
>> With additional bind-mounts of /sys, /proc, /run, /dev, /dev/pts you
>> should be able to chroot into the filesystem and perform the necessary
>> tasks.
>>
>> Just as a note: Be careful, to do this only exclusively, say with the
>> respective VMs powered-off. Also, double check to umount / pvchange
>> -n / ... every layer you've built. Also kpartx -d the partitions and
>> unmap the blktap before trying to boot the VM.
>>
>> Good luck!
>>
>> - Stephan
>>
>>
>> Am Sonntag, den 21.06.2015, 12:43 +0200 schrieb France:
>>> Hi,
>>>
>>> after upgrading Ubuntu Linux, the system does not boot, probably because
>> of wrong grub config format:
>>> ( errorInfo: [Traceback (most recent call last):, File
>> "/usr/bin/pygrub", line 808, in ?, fs = fsimage.open(file,
>> part_offs[0], bootfsoptions), IndexError: list index out of range, ])
>>>
>>> How can I get access to disk of this VM, to fix the grub file by hand
>> and try to restart it?
>>> I have CS 4.3 on XS 6.0.2 with ISCSI disk for virtual instances.
>>>
>>> Tnx.
>>> France.
>>
>>
Re: Access root disk after botched upgrade
Posted by Tim Mackey <tm...@gmail.com>.
If that process didn't work, here's another (using XenCenter)
1. Stop the original VM (the one you want to fix). Note it's VM name and
find it in your XenServer resource pool.
2. Create a new VM within CS and start it. Note the VM name and find it
within your XenServer resource pool
3. On the original VM, give the root disk a readily identifiable
description (it'll help in this process)
4. Detach the root disk from the original VM
5. Find the original root disk and attach it to your second VM and note the
device id assigned to it
6. Login to the second VM and mount the original root disk
7. Fix grub
8. Unmount the original root disk
9. Detach original root disk from the second VM
10. Reattach the original root disk to the original VM
11. Start the original VM.
At this point everything should be working (provided grub was the issue).
While I've given the process using XenCenter, it can be done with CLI.
It's just a bit harder to keep track of the correct uuids using the CLI.
Note that in all of this, if you need to move VMs from one host to another,
that's fine, just make certain they are back on their original hosts when
you're done lest CS get confused.
-tim
On Sun, Jun 21, 2015 at 7:14 AM, Stephan Seitz <
s.seitz@secretresearchfacility.com> wrote:
> Hi,
>
> on XenServer I'ld expect your SR containing *.vhd files. You could use
> the cli "xe" command to determine which file is attached. Maybe this
> info can also be seen in the gui.
>
> Here's a short walkthrough, how to access vhd files:
> http://wiki.xen.org/wiki/Mounting_a_.vhd_disk_image_using_blktap/tapdisk
>
> If your vhd file contains partitions, you could do a
> kpartx -a /dev/xen/....
> to get
> /dev/mapper/blktap0p[0....n]
>
> Depending on your guest OS, e.g. If there's LVM or dm-crypt etc...
> inside the following steps vary.
>
> Just use standard linux tools to mount / pvscan / cryptsetup / ...
> the /dev/mapper/blktap... partitions.
>
> With additional bind-mounts of /sys, /proc, /run, /dev, /dev/pts you
> should be able to chroot into the filesystem and perform the necessary
> tasks.
>
> Just as a note: Be careful, to do this only exclusively, say with the
> respective VMs powered-off. Also, double check to umount / pvchange
> -n / ... every layer you've built. Also kpartx -d the partitions and
> unmap the blktap before trying to boot the VM.
>
> Good luck!
>
> - Stephan
>
>
> Am Sonntag, den 21.06.2015, 12:43 +0200 schrieb France:
> > Hi,
> >
> > after upgrading Ubuntu Linux, the system does not boot, probably because
> of wrong grub config format:
> > ( errorInfo: [Traceback (most recent call last):, File
> "/usr/bin/pygrub", line 808, in ?, fs = fsimage.open(file,
> part_offs[0], bootfsoptions), IndexError: list index out of range, ])
> >
> > How can I get access to disk of this VM, to fix the grub file by hand
> and try to restart it?
> > I have CS 4.3 on XS 6.0.2 with ISCSI disk for virtual instances.
> >
> > Tnx.
> > France.
>
>
Re: Access root disk after botched upgrade
Posted by Stephan Seitz <s....@secretresearchfacility.com>.
Hi,
on XenServer I'ld expect your SR containing *.vhd files. You could use
the cli "xe" command to determine which file is attached. Maybe this
info can also be seen in the gui.
Here's a short walkthrough, how to access vhd files:
http://wiki.xen.org/wiki/Mounting_a_.vhd_disk_image_using_blktap/tapdisk
If your vhd file contains partitions, you could do a
kpartx -a /dev/xen/....
to get
/dev/mapper/blktap0p[0....n]
Depending on your guest OS, e.g. If there's LVM or dm-crypt etc...
inside the following steps vary.
Just use standard linux tools to mount / pvscan / cryptsetup / ...
the /dev/mapper/blktap... partitions.
With additional bind-mounts of /sys, /proc, /run, /dev, /dev/pts you
should be able to chroot into the filesystem and perform the necessary
tasks.
Just as a note: Be careful, to do this only exclusively, say with the
respective VMs powered-off. Also, double check to umount / pvchange
-n / ... every layer you've built. Also kpartx -d the partitions and
unmap the blktap before trying to boot the VM.
Good luck!
- Stephan
Am Sonntag, den 21.06.2015, 12:43 +0200 schrieb France:
> Hi,
>
> after upgrading Ubuntu Linux, the system does not boot, probably because of wrong grub config format:
> ( errorInfo: [Traceback (most recent call last):, File "/usr/bin/pygrub", line 808, in ?, fs = fsimage.open(file, part_offs[0], bootfsoptions), IndexError: list index out of range, ])
>
> How can I get access to disk of this VM, to fix the grub file by hand and try to restart it?
> I have CS 4.3 on XS 6.0.2 with ISCSI disk for virtual instances.
>
> Tnx.
> France.