On 05/10/2011 06:56 AM, Jonathan Disher wrote:
> In a previous life, I've had extreme problems with XFS, including
> kernel panics and data loss under high load.
>
> Those were database servers, not Hadoop nodes, and it was a few years
> ago. But, ext3/ext4 seems to be stable enough, and it's more widely
> supported, so it's my preference.
>
> -j
>
> On May 10, 2011, at 3:59 AM, Rita wrote:
>
>> I keep asking because I wasn't able to use a XFS filesystem larger
>> than 3-4TB. If the XFS file system is larger than 4TB hdfs won't
>> recognize the space. I am on a 64bit RHEL 5.3 host.
>>
>>
>> On Tue, May 10, 2011 at 6:30 AM, Will Maier <wcmaier@hep.wisc.edu
>> <mailto:wcmaier@hep.wisc.edu>> wrote:
>>
>> On Tue, May 10, 2011 at 12:03:09AM -0400, Rita wrote:
>> > what filesystem are they using and what is the size of each
>> filesystem?
>>
>> It sounds nuts, but each disk has its own ext3 filesystem. Beyond
>> switching to
>> the deadline IO scheduler, we haven't done much tuning/tweaking.
>> A script runs
>> every ten minutes to test all of the data mounts and reconfigure
>> hdfs-site.xml
>> and restart the datanode if necessary. So far, this approach has
>> allowed us to
>> avoid loss of space to RAID without correlating the risk of disk
>> failure by
>> building larger RAID0s.
>>
>> In the future, we expect to deprecate the script and rely on the
>> datanode process
>> itself to handle missing/failing disks.
>>
>> --
>>
>> Will Maier - UW High Energy Physics
>> cel: 608.438.6162 <tel:608.438.6162>
>> tel: 608.263.9692 <tel:608.263.9692>
>> web: http://www.hep.wisc.edu/~wcmaier/
>> <http://www.hep.wisc.edu/%7Ewcmaier/>
>>
>>
>>
>>
>> --
>> --- Get your facts first, then you can distort them as you please.--
>
Jonathan, I had the same issues on my PostgreSQL servers, and the main
issues was given by the kernel version that I was using.
I upgrade the kernel to the last version supported by Red Hat, and
everything worked OK.
My prefered filesystem is ZFS, It's a shame that Linux support is very
inmature yet. For that reason, I changed my PostgreSQL hosts to
FreeBSD-8.0 to use
ZFS like filesystem and it's really rocks.
Had anyone tested a Hadoop cluster with this filesystem?
On Solaris or FreeBSD?
Regards
--
Marcos Luís Ortíz Valmaseda
Software Engineer (Large-Scaled Distributed Systems)
University of Information Sciences,
La Habana, Cuba
Linux User # 418229
http://about.me/marcosortiz
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