binary NULL errors

binary NULL errors

[Christoph Anton Mitterer]

Hi.

I've got some questions about using XFS.

I've already used it as for all my discs about one or two years ago, but
then I've suffered several times from the binary NULLs "bug", that
happened when the system crashed or had a power loss.

I've lost more than one open files (like all my bookmarks in Firefox)
and thus I've switched back to ext3

In the FAQ at http://oss.sgi.com/projects/xfs/faq.html it says:
Update: This issue has been addressed with a CVS fix on the 29th March
2007 and merged into mainline on 8th May 2007 for 2.6.22-rc1.

What does this exactly mean and what has been fixed/addressed?
Is XFS now similar to ext3 and I won't see those binary NULLs stuff
again?

What happens now in case of a powerloss? Does XFS still make heavy use
of caching techniques?

Best wishes,
Chris,

Re: binary NULL errors

[David Chinner]

On Mon, Jan 14, 2008 at 07:05:49PM +0100, Christoph Anton Mitterer wrote:
> In the FAQ at http://oss.sgi.com/projects/xfs/faq.html it says:
> Update: This issue has been addressed with a CVS fix on the 29th March
> 2007 and merged into mainline on 8th May 2007 for 2.6.22-rc1.
> 
> What does this exactly mean and what has been fixed/addressed?

It means exactly what it says - that the problem has been fixed if
you use 2.6.22 or more recent.  If you want details, start looking
here:

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ba87ea699ebd9dd577bf055ebc4a98200e337542

> Is XFS now similar to ext3 and I won't see those binary NULLs stuff
> again?

Yes, It will behave the same as ext3 - either you'll have a good
file or you'll see a zero length file (because the application
doesn't overwrite safely).

> What happens now in case of a powerloss?

Same thing as always happens on power loss - you lose whatever
is in memory. We're just more careful about how we update stuff
on disk now.

> Does XFS still make heavy use
> of caching techniques?

Yes, just like every other linux filesystem ;)

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group