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Posted to common-user@hadoop.apache.org by 신승엽 <mi...@naver.com> on 2009/05/22 10:50:34 UTC
input/output error while setting up superblock
Hi, I have a problem to use hdfs.
I mounted hdfs using fuse-dfs.
I created a dummy file for 'Xen' in hdfs and then formated the dummy file using 'mke2fs'.
But the operation was faced error. The error message is as follows.
[root@localhost hdfs]# mke2fs -j -F ./file_dumy
mke2fs 1.40.2 (12-Jul-2007)
./file_dumy: Input/output error while setting up superblock
Also, I copyed an image file of xen to hdfs. But Xen couldn't the image files in hdfs.
root@localhost hdfs]# fdisk -l fedora6_demo.img
last_lba(): I don't know how to handle files with mode 81a4
You must set cylinders.
You can do this from the extra functions menu.
Disk fedora6_demo.img: 0 MB, 0 bytes
255 heads, 63 sectors/track, 0 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
fedora6_demo.img1 * 1 156 1253038+ 83 Linux
Could you answer me anything about this problem.
Thank you.
Re: input/output error while setting up superblock
Posted by Amr Awadallah <aa...@cloudera.com>.
You should take a look at GlusterFS, it should be a good fit for this
kind of workload:
http://www.gluster.org/
-- amr
Aaron Kimball wrote:
> More specifically:
>
> HDFS does not support operations such as opening a file for write/append
> after it has already been closed, or seeking to a new location in a writer.
> You can only write files linearly; all other operations will return a "not
> supported" error.
>
> You'll also find that random-access read performance, while implemented, is
> not particularly high-throughput. For serving Xen images even in read-only
> mode, you'll likely have much better luck with a different FS.
>
> - Aaron
>
>
> 2009/5/22 Taeho Kang <tk...@gmail.com>
>
>
>> I don't think HDFS is a good place to store your Xen image file as it will
>> likely be updated/appended frequently in small blocks. With the way HDFS is
>> designed for, you can't quite use it like a regular filesystem (e.g. ones
>> that support frequent small block appends/updates in files). My suggestion
>> is to use another filesystem like NAS or SAN.
>>
>> /Taeho
>>
>> 2009/5/22 신승엽 <mi...@naver.com>
>>
>>
>>> Hi, I have a problem to use hdfs.
>>>
>>> I mounted hdfs using fuse-dfs.
>>>
>>> I created a dummy file for 'Xen' in hdfs and then formated the dummy file
>>> using 'mke2fs'.
>>>
>>> But the operation was faced error. The error message is as follows.
>>>
>>> [root@localhost hdfs]# mke2fs -j -F ./file_dumy
>>> mke2fs 1.40.2 (12-Jul-2007)
>>> ./file_dumy: Input/output error while setting up superblock
>>> Also, I copyed an image file of xen to hdfs. But Xen couldn't the image
>>> files in hdfs.
>>>
>>> root@localhost hdfs]# fdisk -l fedora6_demo.img
>>> last_lba(): I don't know how to handle files with mode 81a4
>>> You must set cylinders.
>>> You can do this from the extra functions menu.
>>>
>>> Disk fedora6_demo.img: 0 MB, 0 bytes
>>> 255 heads, 63 sectors/track, 0 cylinders
>>> Units = cylinders of 16065 * 512 = 8225280 bytes
>>>
>>> Device Boot Start End Blocks Id System
>>> fedora6_demo.img1 * 1 156 1253038+ 83 Linux
>>>
>>> Could you answer me anything about this problem.
>>>
>>> Thank you.
>>>
>>>
>
>
Re: input/output error while setting up superblock
Posted by Aaron Kimball <aa...@cloudera.com>.
More specifically:
HDFS does not support operations such as opening a file for write/append
after it has already been closed, or seeking to a new location in a writer.
You can only write files linearly; all other operations will return a "not
supported" error.
You'll also find that random-access read performance, while implemented, is
not particularly high-throughput. For serving Xen images even in read-only
mode, you'll likely have much better luck with a different FS.
- Aaron
2009/5/22 Taeho Kang <tk...@gmail.com>
> I don't think HDFS is a good place to store your Xen image file as it will
> likely be updated/appended frequently in small blocks. With the way HDFS is
> designed for, you can't quite use it like a regular filesystem (e.g. ones
> that support frequent small block appends/updates in files). My suggestion
> is to use another filesystem like NAS or SAN.
>
> /Taeho
>
> 2009/5/22 신승엽 <mi...@naver.com>
>
> > Hi, I have a problem to use hdfs.
> >
> > I mounted hdfs using fuse-dfs.
> >
> > I created a dummy file for 'Xen' in hdfs and then formated the dummy file
> > using 'mke2fs'.
> >
> > But the operation was faced error. The error message is as follows.
> >
> > [root@localhost hdfs]# mke2fs -j -F ./file_dumy
> > mke2fs 1.40.2 (12-Jul-2007)
> > ./file_dumy: Input/output error while setting up superblock
> > Also, I copyed an image file of xen to hdfs. But Xen couldn't the image
> > files in hdfs.
> >
> > root@localhost hdfs]# fdisk -l fedora6_demo.img
> > last_lba(): I don't know how to handle files with mode 81a4
> > You must set cylinders.
> > You can do this from the extra functions menu.
> >
> > Disk fedora6_demo.img: 0 MB, 0 bytes
> > 255 heads, 63 sectors/track, 0 cylinders
> > Units = cylinders of 16065 * 512 = 8225280 bytes
> >
> > Device Boot Start End Blocks Id System
> > fedora6_demo.img1 * 1 156 1253038+ 83 Linux
> >
> > Could you answer me anything about this problem.
> >
> > Thank you.
> >
>
Re: input/output error while setting up superblock
Posted by Taeho Kang <tk...@gmail.com>.
I don't think HDFS is a good place to store your Xen image file as it will
likely be updated/appended frequently in small blocks. With the way HDFS is
designed for, you can't quite use it like a regular filesystem (e.g. ones
that support frequent small block appends/updates in files). My suggestion
is to use another filesystem like NAS or SAN.
/Taeho
2009/5/22 신승엽 <mi...@naver.com>
> Hi, I have a problem to use hdfs.
>
> I mounted hdfs using fuse-dfs.
>
> I created a dummy file for 'Xen' in hdfs and then formated the dummy file
> using 'mke2fs'.
>
> But the operation was faced error. The error message is as follows.
>
> [root@localhost hdfs]# mke2fs -j -F ./file_dumy
> mke2fs 1.40.2 (12-Jul-2007)
> ./file_dumy: Input/output error while setting up superblock
> Also, I copyed an image file of xen to hdfs. But Xen couldn't the image
> files in hdfs.
>
> root@localhost hdfs]# fdisk -l fedora6_demo.img
> last_lba(): I don't know how to handle files with mode 81a4
> You must set cylinders.
> You can do this from the extra functions menu.
>
> Disk fedora6_demo.img: 0 MB, 0 bytes
> 255 heads, 63 sectors/track, 0 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
>
> Device Boot Start End Blocks Id System
> fedora6_demo.img1 * 1 156 1253038+ 83 Linux
>
> Could you answer me anything about this problem.
>
> Thank you.
>