[OpenAFS] Disk cache not updating

[Jeffrey Altman]

Brian:

Useful information would be the OpenAFS version number you have 
installed.  I have no idea what is the latest OpenAFS rpm available
translates to.

Does it appear from the output of "cmdebug <host> -long" that you
have callbacks for volume in question?  cmdebug lists cache entries
with an ID of the form:  <cellID>.<volID>.<vnode>.<unique>  Using
volume ID you can search the output for entries from the specified
volume and look to see if there is a callback address and a non-zero
expiration time.

Do you have a callback after the "fs flushvol" command is issued?

If you have a callback after the "fs flushvol" and it does not get
renewed at expiration, then there is a bug somewhere.  Perhaps you
are correct in that it is triggered by load.  If so it might be
caused by reference count overflow.  Do any of the reference counts
in the cmdebug output display as negative?

If you do have callbacks and do not see the changes, the second
most likely cause is that the messages from the afs file server
to the client are blocked somewhere.

Jeffrey Altman



Brian Huntley wrote:

> 
> Hello everyone...
> 
> I can't seem to find anything on this particular type of cache problem, 
> so hopefully someone can point me in the right direction.
> 
> We recently put into production a webserver whose document root is in 
> AFS.  During the development of this system, we never had an issue with 
> the AFS client keeping it's cache current with what was on the server. 
>  Since it's been put into production, however, we are finding that we 
> frequently must use fs flushvol to keep the cache up to date with the 
> AFS server's version of volumes.  It seems that the volumes most heavily 
> hit by apache are the ones that most often need a flush to stay current.
> 
> I can only hypothesize that this is therefore a transaction/load related 
> issue.  The webserver itself is virtually idle, but serves tens of 
> thousands of requests per day.
> 
> We're running RedHat Enterprise 3, Update 3 and the latest OpenAFS rpm 
> available for it.
> 
> Any thoughts?
> 
> TIA!
> -b
> --
> Brian T. Huntley, Manager of Network Operations
> Office of Information Technology
> Clarkson University
> bhuntley@clarkson.edu -- 315.268.6723
> "UNIX *is* user friendly. It's just selective about who its friends are."