[CentOS] 40TB File System Recommendations

Mon Apr 18 16:27:56 UTC 2011
Ross Walker <rswwalker at gmail.com>

On Apr 17, 2011, at 3:05 AM, Charles Polisher <cpolish at surewest.net> wrote:

> On Wed, Apr 13, 2011 at 11:55:08PM -0400, Ross Walker wrote:
>> On Apr 13, 2011, at 9:40 PM, Brandon Ooi <brandono at gmail.com> wrote:
>> 
>>> On Wed, Apr 13, 2011 at 6:04 PM, Ross Walker <rswwalker at gmail.com> wrote:
>>>> 
>>>> One was a hardware raid over fibre channel, which silently corrupted
>>>> itself. System checked out fine, raid array checked out fine, xfs was
>>>> replaced with ext3, and the system ran without issue.
>>>> 
>>>> Second was multiple hardware arrays over linux md raid0, also over fibre
>>>> channel. This was not so silent corruption, as in xfs would detect it
>>>> and lock the filesystem into read-only before it, pardon the pun, truly
>>>> fscked itself. Happened two or three times, before we gave up, split up
>>>> the raid, and went ext3, Again, no issues.
>>> 
>>> Every now and then I hear these XFS horror stories. They seem too
>>> impossible to believe.
>>> 
>>> Nothing breaks for absolutely no reason and failure to know where
>>> the breakage was shows that maybe there wasn't adequately skilled
>>> techinicians for the technology deployed.
>>> 
>>> XFS if run in a properly configured environment will run flawlessly.
> 
> Here's some deconstruction of your argument:
> 
>    "... and failure to know where the breakage was shows that maybe there
>     wasn't adequately skilled techinicians for the technology deployed"
> 
> This is blaming the victim. One must have the time, skills and
> often other resources to do root cause analysis.
> 
>    "XFS if run in a properly configured environment will run flawlessly." 
> 
> I think a more narrowly qualified opinion is appropriate: "XFS,
> properly configured, running on perfect hardware atop a perfect
> kernel, will have fewer serious bugs than it had on Jan 1, 2009."
> Here's a summary of XFS bugzilla data from 2009 through today:

I already apologized for those comments last week. No need to keep flogging a dead horse here.


>                                 Bug Status
>    Severity    
>                  NEW     ASSIGNED    REOPENED    Total
>    blocker         3            .           .        3
>    critical       10            2           .       12
>    major          48            2           .       50
>    normal        118           46           3      167
>    minor          26            3           .       29
>    trivial         7            .           .        7
>    enhancement    39            9           1       49
>    Total         251           62           4      317
> 
> See also the XFS mailing list for a big dose of reality. Flawlessly
> is not the label I would use for XFS. /Maybe/ for Ext2.

Basically it comes down to that all file systems, as do all software, have bugs and edge cases and thinking that one can find a file system that is bug free is naive.

Test, test, test.

-Ross