picking a filesystem

On Wed, May 25, 2011 at 4:41 PM, Greg Smith <greg(at)2ndquadrant(dot)com> wrote:
> On 05/23/2011 06:16 PM, John Rouillard wrote:
>>
>> OS: centos 5.5
>> Filesystem: data - ext4 (note 4 not 3); 6.6T formatted
>>             wal  - ext4; 1.5T formatted
>> Raid: data - level 10, 8 disk wd2003; controller LSI MegaRAID SAS 9260-4i
>>       wal  - level 1,  2 disk wd2003; controller LSI MegaRAID SAS 9260-4i
>>
>> Could it be an ext4 issue? It seems that ext4 may still be at the
>> bleeding edge for postgres use.
>>
>
> I would not trust ext4 on CentOS 5.5 at all.  ext4 support in 5.5 is labeled
> by RedHat as being in "Technology Preview" state.  I believe that if you had
> a real RedHat system instead of CentOS kernel, you'd discover it's hard to
> even get it installed--you need to basically say "yes, I know it's not for
> production, I want it anyway" to get preview packages.  It's not really
> intended for production use.
>
> What I'm hearing from people is that they run into the occasional ext4 bug
> with PostgreSQL, but the serious ones aren't happening very often now, on
> systems running RHEL6 or Debian Squeeze.  Those kernels are way, way ahead
> of the ext4 backport in RHEL5 based systems, and they're just barely stable.

So if you're running a RHEL5.4 or RHEL5.5 system, are you basically
stuck with ext3? I'm not sure if I'm remembering correctly, but ISTM
that you've been uncomfortable with BOTH ext4 and XFS prior to RHEL6;
but OK with both beginning with RHEL6.

Also, any tips on mount options for XFS/ext4/ext3?

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company