On 05/10/2011 06:29 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 <wcma...@hep.wisc.edu
<mailto:wcma...@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.--
I saw this problem before with 64 bits version of Red Hat EL 5.3.
Which is the kernel version that you are using?
Can you upgrade the system to 5.5 or to 6.0? There are a lot of bugs
corrections and performance gaining with these releases.
Another issue is that since the 5.4 vesion, Red Hat added preliminary
XFS support specifically to address the need for filesystem more
large, and their RHEL 6 release treats it as a fully supported
filesystem on par with ext3 and ext4.
One last issue: XFS can handle files greather than 16 TB. The primary
problem is the tools to read and write those files. (ext4 virtually too can
handle this huge files, but the problems is on the mkfs utility that is
not optimized for this)
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
