[Linux-cluster] 'df' not accurate?

[Brynnen R Owen]

On Mon, Nov 22, 2004 at 05:16:04PM +0800, David Teigland wrote:
> On Thu, Nov 18, 2004 at 05:24:42PM -0600, Ken Preslan wrote:
> > GFS caches the information used to perform a "df" in little chunks of
> > cluster memory (called LVBs) associated with each bitmap lock.  The data
> > probably got corrupted somehow.  The "gfs_tool reclaim" caused the
> > data to be reinitialzed from disk.  ("Gfs_tool shrink" should have done
> > that too.  I'm not sure why it didn't.)
> > 
> > Maybe there's a bug in the lock_dlm LVB recovery code or a bug has crept
> > into the filesystem code.
> 
> There was a bug updating lvb's in the dlm.  The problem should now be
> fixed.

Great!

  I have discovered a second problem, although this may be out of
date.  If these problems have been addressed, or if the above bugfix
addresses these, I'll try again with the latest snapshot.

  I had problems with the Nov 11 CVS snapshot version of 'ccsd'
segfaulting and filesystem corruption.  I set up a cluster with 5
computers.  I created a brand new GFS filesystem and set two of the
machines copying from ext3 on IDE filesystems to one GFS on Fibre
filesystem.  Both machines finished the task.  One machine copied
about 250G, the other copied about 30G.  I then unmounted the
filesystem and ran gfs_fsck.  There were several errors, including
datablock pointers out of range.  I noticed that ccsd had died on
several machines, and they weren't in the fence domain.  I decided
that was the issue, so I brought the cluster down and back up, made
sure everything was in the same fence domain, recreated the GFS and
reran the test.  While ccsd was not dead this time, the GFS filesystem
still showed several errors.

  I then moved to the latest CVS snapshot (Nov 21) and lock_gulm, and
am waiting for the copy to finish so I can report on the results.

-- 
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<>  Brynnen Owen            (     this space for rent                      )<>
<>  owen at uiuc.edu           (                                              )<>
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