[OpenAFS] OpenAFS+Samba file locking issues

Eric Chris Garrison ecgarris@iupui.edu
Fri, 23 Oct 2009 15:10:09 -0400

Well, my issue with large volume moves isn't solved, but I've gotten
everything moved this time. Had to resort to making a copy of a volume and
then doing some quick renaming to make the copy the real volume and
removed the original volume.  Everything's moved to the new disk arrays
now at least.

Anyway, we have a different, nagging problem.  We have a few users who
have complained that if they open and try to write to a Powerpoint 2007
file, they get a "read only" error like "K:\ecgtest.pptx is read-only.  Do
you want to save changes to a different file name?"  Actually, they only
get it about 1 in 4 tries.

I've been able to reproduce this, but only as a normal user... an admin
account in AFS never has this problem.  It seems like if I always stay
attached to one gateway server only, I never get the error.

So, I think it's some kind of file locking issue, possibly due to
disconnecting and reconnecting to another server due to round-robin, but
I'm not sure that's the actual case, it's just a theory at this point. The
users have claimed to map to a specific machine and then get the error
anyway, but I haven't been able to reproduce that so far.

We get a lot of errors in the logs that say, "kernel: afs: byte-range
lock/unlock ignored; make sure no one else is running this program."
That's probably from openafs-client since it's kernel-level where smbd
isn't.  Not sure if that's related. The intermittent nature of the problem
makes it especially frustrating.  Samba logs don't even indicate a problem
at the time of the error message, so I guess it's all on the client's side.

There's not a lot of information about using AFS through Samba out there.
 I'm sure it'd be better to make the users use the OpenAFS client, but we
have a large segment who don't want to mess with it, including some of the
support organizations on the various campuses.

Any advice on this perplexing issue would be greatly appreciated.  I'd
offer a reward of a six pack of my homebrewed beer if someone has a
working answer, but it's not technically legal to ship liquids anymore in
the US...


Eric Chris Garrison             | Principal Mass Storage Specialist
ecgarris@iupui.edu              | Indiana University - Research Storage
W: 317-278-1207 M: 317-250-8649 | Jabber IM: ecgarris@iupui.edu