[CentOS] 40TB File System Recommendations

[Charles Polisher]

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:

                                 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.
-- 
Charles Polisher