[OpenAFS] afs memcache tuning... lockups in afs_cv_wait

Mike Garrison mcgarr@umich.edu
Wed, 13 Feb 2008 20:01:40 -0500

On Feb 12, 2008, at 10:46 PM, Mike Polek wrote:

> Hello, all,
>  I'm working on some performance tuning using Linux servers with
> AFS clients and ftp server software to shuttle data from users
> on the net to my AFS file servers. While working on tuning
> things for performance and stability, the number one issue
> I run into is that if things get "too busy," all the processes
> go into a holding pattern where ps axo wchan shows them all
> in afs_cv_wait.
>   [snip]
>  Any tips/pointers? I'm ok with just capping the usage
> and declaring the limit to be somewhere below the threshold
> where things go horribly wrong. But if there is a way to
> get performance to degrade gracefully under a high load,
> that would be preferred.
>  And if I forgot to post some important vital and
> super obvious piece of information... apologies in advance. ;-)

What parameters are you using for the client? What's rxdebug <client> - 
port 7001 -rxstats show?

Mike Garrison