attack upon XFS, misinformation abounds, linux-raid list

[Stefan Ring]

On Sun, Jun 9, 2013 at 12:46 PM, Stan Hoeppner <stan at hardwarefreak.com> wrote:
> In a recent linux-raid list thread here:
> http://marc.info/?l=linux-raid&m=137072140106867&w=2
>
> seriously flawed arguments against the reliability of XFS, and even the
> performance of XFS, are made.  The OP even quotes Dave's LCA
> presentation as a performance reason to avoid XFS.  The party really
> gets started at paragraph 7.
>
> I made a brief effort to debunk his claims and explained that he can't
> have O_PONIES, that he should use fsync or O_DIRECT, etc for data
> safety.  To non experts/advanced filesystem users, his long winded
> argument may be persuasive.  Obviously none of you experts has time to
> debunk every such post, but this one may be worth a read at least,
> especially given the weight Google gives to vger lists.

The really unfortunate thing about this is that the bug[1] which would
prevent transaction flushing from happening got imported and shipped
for a rather long time in RHEL. It's one thing to get a file zeroed
that's a few seconds old, but having the same happen to files which
haven't been touched in hours, even before issuing manual sync, is
certainly not very reassuring.

As a very satisfied user of XFS on CentOS 6, I have been nervous
enough about that to go through the trouble of rebooting our main
server for a kernel upgrade a few weeks ago. Thanks to RedHat's
deceptive tactics regarding kernel patches, I have also not been able
to pin-point the exact range of kernel versions affected by this in a
reasonable amount of time and hence have not found out (thankfully not
the hard way) if it was even necessary.

[1] https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/6.4_Technical_Notes/kernel.html
"BZ#855139"