Eric,
Thanks for the detailed explanation.
I have just done a xfsdump level 0, so everything should be clean now.
Greg
>> Hi Greg -
>> Sorry, I didn't explain things very well, let me try to do better. :)
>> XFS preallocates space at the end of the file, assuming that you'll
>> probably use it, and things will be more efficient that way. When you
>> close the file, this "extra" space is removed.
>> Somehow, some files on your filesystem seem to be in the state where
>> these preallocated blocks are still hanging out there past EOF. This
>> isn't really a problem, everything is consistent, there are just more
>> blocks than need to be there for the data. The next time you open &
>> close the file, those blocks will be removed...
>> ... unless you magically transport those files to a read-only device, as
>> in the case of your snapshot. In that case, when you open & close the
>> file, xfs was trying to clean up after itself, but the I/O failed (due
>> to the readonly nature of the device) and the fs shut down. (And the
>> kernel apparently oopsed after that... which is a different problem...
>> :/)
>> So, this new kernel will not try to clean up these past-EOF-blocks on a
>> readonly device.
>> The original files may still be on the "live" filesystem in this state,
>> for whatever reason. They can be "fixed up" by opening & closing them,
>> as tarring up the whole "live" filesystem would do.
>> IOW, your new CVS kernel is only avoiding the problem on the readonly
>> device; if you open & close the original files with either kernel, the
>> problem will go away, and either kernel should work again with the
>> snapshot.
>> -Eric
>> On Thu, 2002-10-31 at 12:34, Greg Freemyer wrote:
>> > Thanks Eric,
>> >
>> > Current CVS kernel does indeed allow my backup to run.
>> >
>> > It is obvious that you guys have made a number of improvements in
>> XFS/LVS integration in the last several months.
>> >
>> > I'm looking forward to the real 1.2 release.
>> >
>> > One question: do I still have an unusual data/meta-data problem on my LV
>> that this kernel handles better Or did this kernel fix the on disk data
>> itself and now I could go back to the old kernel?
>> >
>> > Greg
>> --
>> Eric Sandeen XFS for Linux http://oss.sgi.com/projects/xfs
>> sandeen@xxxxxxx SGI, Inc. 651-683-3102
Greg Freemyer
Internet Engineer
Deployment and Integration Specialist
Compaq ASE - Tru64 v4, v5
Compaq Master ASE - SAN Architect
The Norcross Group
www.NorcrossGroup.com
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