Re: Performance of ext4

[Holger Kiehl]

On Thu, 19 Jun 2008, Theodore Tso wrote:

> On Tue, Jun 17, 2008 at 11:42:36AM +0000, Holger Kiehl wrote:
> > Note how the size of file results.24033.helena.dwd.de changes from
> > 9230 before the test to 8208 bytes after the test. Also note the
> > date both have the same timestamp "2008-06-17 04:35". I have made a
> > copy of results.24033.helena.dwd.de before the test and compared it
> > with that after the test. The file is just truncated by 1022 bytes
> > and there is no garbage.
>
> So the corruption is always a truncation, correct?
Correct.

> Did you notice the problem with ext4 w/o the patch queue?
No, without patch queue it I did not not notice the problem.

> I have a
> suspicion that the problem may have been introduced by the delayed
> allocation code, but I don't have hard evidence.  When you rerun your
> benchmark (which seems to be the closest thing we have to a
> reproduction case), it would be interesting to know if the problem
> goes away with -o nodelalloc (again, it would localize where we need
> to look).
Ok I will do thats soon as I have a system available.

Holger

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