We upgraded the gateways mentioned in the original email to
openafs-client-1.6.6-0.pre1 awhile back, since there was a bugfix for cache
overrun in it (thanks for the help, Derrick). And for awhile it seemed like
it had worked, our AFS clients on the gateway hosts weren't locking up.

But the problem is back. We've had many lockups, requiring reboot, over the
past month, usually happening in clusters, like a user locking up one host,
them moving to another to lock it up.

After taking "smbstatus" snapshots each time it locks up, I've finally found
a common factor: large Outlook .pst files being locked:

One host:

4229         46516      DENY_ALL   0x7019f     RDWR       NONE
/afs/iu.edu/home/b/e/xxxxxx
[email protected]/BL-ECON-WY214-1/Data/C/Users/xxxxxx/Documents/Outlook
Files/Xxx
x Xxxxxx E-Mail Archive (2006-2011) (2014_02_27 18_02_49 UTC).pst   Mon Mar
3 13:57:23 201412868        46516      DENY_ALL   0x7019f     RDWR
NONE             /afs/iu.edu/home/b/e/xxxxxx
[email protected]/BL-ECON-WY214-1/Data/C/Users/xxxxxx/Documents/Outlook
Files/Xxxx Xxxxxx E-Mail Archive (2006-2011) (2014_02_27 18_02_49 UTC).pst
Mon Mar  3 16:30:32 2014
30686        46516      DENY_ALL   0x7019f     RDWR       NONE
/afs/iu.edu/home/b/e/xxxxxx
[email protected]/BL-ECON-WY214-1/Data/C/Users/xxxxxx/Documents/Outlook
Files/Xxxx Xxxxxx E-Mail Archive (2006-2011) (2014_02_27 18_02_49 UTC).pst
Thu Mar  6 14:53:39 2014

On another host:

/home/b/e/xxxxxx   
[email protected]/BL-ECON-WY214-1/Data/C/Users/xxxxxx/Documents/Outlook
Files/Xxxx Xxxxxx E-Mail Archive (2006-2011) (2014_02_27 18_02_49 UTC).pst
Mon Mar  3 15:21:53 2014
ecg-ss2:24849        46516      DENY_ALL   0x7019f     RDWR       NONE
/afs/iu.edu/home/b/e/xxxxxx
[email protected]/BL-ECON-WY214-1/Data/C/Users/xxxxxx/Documents/Outlook
Files/Xxxx Xxxxxx E-Mail Archive (2006-2011) (2014_03_06 18_11_27 UTC).pst
Thu Mar  6 14:44:26 2014

These are always present on each host that's locked up. Same .pst file,
even. It is a 6.5 GB file. Our AFS client cache is 7GB in size on a 9GB
partition.

I'm writing to the user to see if he's doing anything extraordinary.

Still looking for ideas. I haven't tried Kim Kaball's idea of lowering the
cache size to 2.5GB, I may try that next, but I worry that it'll impact
performance too much.

Thanks!!!

Chris Garrison
Indiana University 
UITS Research Storage

From:  Chris Garrison <[email protected]>
Date:  Wednesday, November 20, 2013 4:47 PM
To:  "[email protected]" <[email protected]>
Subject:  [OpenAFS] OpenAFS client cache overrun?

Hello,

We have some RHEL 5.5 servers with openafs-client-1.6.1-1 running. There are
4 of them in a round-robin DNS, with Apache and Samba sitting on top of
OpenAFS filesystem.

The hosts' /etc/sysconfig/openafs files look like this:

  # OpenAFS Client Configuration
  AFSD_ARGS="-dynroot -fakestat-all -daemons 8 -chunksize 22"

The hosts' /usr/vice/etc/cacheinfo files look like this:

  /afs:/usr/vice/cache:7500000

I realize it's better for users to all use the openafs client for their own
OS, but we have a large base of users who insist on wanting to just map a
drive without installing a client. We have been running like this for 8+
years now, it's not a new setup.

Something has been locking up the openafs client in the past month or so.
The cache will show as more and more full in "df" and then at some point,
AFS stops answering, and any attempt to do a directory listing or to access
a file results in a zombie process.

The zombie processes mount up fast, the load on the machine skyrockets, and
the only solution seems to be to reboot.

What could cause that lockup? It's usually only on one host at a time, and
seems like it will "move" from host to host, even returning to the same host
in the same day after reboot once in awhile.

I doubled the cache size on these hosts, and it seemed to slow things down,
but we had another lockup today after a restart of all the clients on Sunday
during a hardware upgrade on the SAN, so no host had been running more than
3 days.

To me, it feels like maybe someone is forcing a huge file through and
running the machine out of cache. Though if that's so, I wonder why it only
just started happening after all these years. If nothing else, it seems like
something new is going on with the user end that's causing it.

Any help would be appreciated, anything from a fix by limiting something in
the openafs client or the cache or ideas as to what someone could be doing.
Because at this point, it's like a denial of service attack that's making
lots of problems for us.

Thank you,

Chris Garrison
Indiana University Research Storage


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