* Re: attack upon XFS, misinformation abounds, linux-raid list
2013-06-09 10:46 attack upon XFS, misinformation abounds, linux-raid list Stan Hoeppner
@ 2013-06-09 12:13 ` Ric Wheeler
2013-06-10 9:43 ` Stefan Ring
` (2 subsequent siblings)
3 siblings, 0 replies; 7+ messages in thread
From: Ric Wheeler @ 2013-06-09 12:13 UTC (permalink / raw)
To: xfs
On 06/09/2013 06:46 AM, Stan Hoeppner 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.
Thanks for pointing that out - I responded as well.
Funny that he decided to use ext4 after basing it on a google search for "xfs
zero" and did not bother to the same query with "ext4 zero length files" :)
Ric
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^ permalink raw reply [flat|nested] 7+ messages in thread* Re: attack upon XFS, misinformation abounds, linux-raid list
2013-06-09 10:46 attack upon XFS, misinformation abounds, linux-raid list Stan Hoeppner
2013-06-09 12:13 ` Ric Wheeler
@ 2013-06-10 9:43 ` Stefan Ring
2013-06-10 13:44 ` Eric Sandeen
2013-06-10 20:02 ` Ben Myers
2013-06-11 7:12 ` Steve Bergman
3 siblings, 1 reply; 7+ messages in thread
From: Stefan Ring @ 2013-06-10 9:43 UTC (permalink / raw)
To: stan; +Cc: xfs@oss.sgi.com
On Sun, Jun 9, 2013 at 12:46 PM, Stan Hoeppner <stan@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"
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: attack upon XFS, misinformation abounds, linux-raid list
2013-06-10 9:43 ` Stefan Ring
@ 2013-06-10 13:44 ` Eric Sandeen
0 siblings, 0 replies; 7+ messages in thread
From: Eric Sandeen @ 2013-06-10 13:44 UTC (permalink / raw)
To: Stefan Ring; +Cc: stan, xfs@oss.sgi.com
On 6/10/13 4:43 AM, Stefan Ring wrote:
> On Sun, Jun 9, 2013 at 12:46 PM, Stan Hoeppner <stan@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.
Bugs and regressions are always unfortunate, and this one was no exception.
It was pretty obscure, but we (mostly Dave) worked with our customers
to identify & resolve it within days of the bug report.
As far as I know, the bug existed only for a crash, not a reboot.
> 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
deceptive - adj. - Giving an appearance or impression different from the true one; misleading.
which sounds pretty damning. Perhaps more accurate is:
obfuscated - adj. - Rendered obscure, unclear, or unintelligible ;)
> 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.
It was introduced in 6.2 and resolved in 6.4, as well as 6.2
and 6.3 z-stream kernels. Those are the sorts of things Red Hat support
can help customers identify more quickly & clearly.
-Eric
> [1] https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/6.4_Technical_Notes/kernel.html
> "BZ#855139"
>
> _______________________________________________
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> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs
>
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: attack upon XFS, misinformation abounds, linux-raid list
2013-06-09 10:46 attack upon XFS, misinformation abounds, linux-raid list Stan Hoeppner
2013-06-09 12:13 ` Ric Wheeler
2013-06-10 9:43 ` Stefan Ring
@ 2013-06-10 20:02 ` Ben Myers
2013-06-11 7:12 ` Steve Bergman
3 siblings, 0 replies; 7+ messages in thread
From: Ben Myers @ 2013-06-10 20:02 UTC (permalink / raw)
To: Stan Hoeppner; +Cc: xfs
Hey Stan,
On Sun, Jun 09, 2013 at 05:46:21AM -0500, Stan Hoeppner 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.
I gave it a quick read, but since I'm not on linux-raid I don't have a good way
to reply to Steve. Could you bounce that message over? I'd be happy to try to
address a point or two...
Thanks,
Ben
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: attack upon XFS, misinformation abounds, linux-raid list
2013-06-09 10:46 attack upon XFS, misinformation abounds, linux-raid list Stan Hoeppner
` (2 preceding siblings ...)
2013-06-10 20:02 ` Ben Myers
@ 2013-06-11 7:12 ` Steve Bergman
2013-06-12 1:12 ` Stan Hoeppner
3 siblings, 1 reply; 7+ messages in thread
From: Steve Bergman @ 2013-06-11 7:12 UTC (permalink / raw)
To: linux-xfs
Stan Hoeppner <stan <at> hardwarefreak.com> writes:
> but this one may be worth a read at least
How flattering that you felt you needed to seek out reinforcements. :-)
-Steve
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^ permalink raw reply [flat|nested] 7+ messages in thread* Re: attack upon XFS, misinformation abounds, linux-raid list
2013-06-11 7:12 ` Steve Bergman
@ 2013-06-12 1:12 ` Stan Hoeppner
0 siblings, 0 replies; 7+ messages in thread
From: Stan Hoeppner @ 2013-06-12 1:12 UTC (permalink / raw)
To: Steve Bergman; +Cc: linux-xfs
On 6/11/2013 2:12 AM, Steve Bergman wrote:
> Stan Hoeppner <stan <at> hardwarefreak.com> writes:
>
>> but this one may be worth a read at least
>
> How flattering that you felt you needed to seek out reinforcements. :-)
More like, "Hay guys, some dude is talking smack about Mom." ;)
Seriously though, expanding the participant list to the devs has been a
positive thing overall, has it not? Worth noting, I've been a
subscriber to the XFS list for a few years--no seeking was required.
--
Stan
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^ permalink raw reply [flat|nested] 7+ messages in thread