Finny that - you must be pretty unique [LWN.net]

Finny that - you must be pretty unique

Posted Mar 15, 2009 3:32 UTC (Sun) by dgc (subscriber, #6611)
In reply to: Finny that - you must be pretty unique by khim
Parent article: Ts'o: Delayed allocation and the zero-length file problem

> If you answer is "don't do this" then how the hell your
> experience is relevant to topic?

XFSQA tests 136-140, 178 and a couple of others "do this"
explicitly and have done so for a couple of years now. This failure
scenario is tested every single time XFSQA is run by a developer.
Run those tests on 2.6.21 and they will fail. Run them on 2.6.22
and they will pass...

FWIW, XFS is alone in the fact that it has:

a) a publicly available automated regression test suite;

(http://git.kernel.org/?p=fs/xfs/xfstests-dev.git;a=summary)

b) a test suite that is run all the time by developers;

c) ioctls and built-in framework to simulate the effect of
power-off crashes that the QA tests use.

This doesn't mean XFS is perfect, but it does mean that it is known
immediately when a regression appears and where we need improvements
to be made.

IOWs, we can *prove* that the (once) commonly seen problems in XFS
have been fixed and will remain fixed. It would be nice if people
recognised this rather relevant fact instead of flaming
indiscriminately about stuff that has been fixed....

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Finny that - you must be pretty unique

Posted Mar 15, 2009 13:15 UTC (Sun) by hmh (subscriber, #3838) [Link]

Some of us do know the XFS guys are doing an excellent job tracking down regressions and bugs :-)

The only thing I never use XFS for is the root filesystem, and that's because nobody has seen fit to fix the XFS fsck to detect it is being run on a read-only filesystem, and to switch to xfs_repair on-the-fly.

It is no fun to need boot CDs to make sure everything is kosher in the root filesystem (or worse, to repair it)...

But it really works well for the MTA queues and squid spool, for example.