[OpenAFS] client tuning using the -daemons option

Derrick Brashear shadow@gmail.com
Tue, 11 Nov 2008 16:43:44 -0500

More daemons means more background fetching and storing, which means
more in-flight requests at any given time. Any one authentication
context can have only 4 calls per server at a time, but for a web
server you probably can use more than just 2 sets of extra calls worth
of daemons.

On Tue, Nov 11, 2008 at 12:00 PM, Jason Edgecombe
<jason@rampaginggeek.com> wrote:
> hi everyone,
> I'm tuning some afs client settings for our Linux 64bit workstations
> (v1.4.7) and for a test Linux web server (v1.4.6). I noticed that
> bumping the -daemons option for afsd from 6 to 16 on the web server
> seems to improve performance along with increasing the stat and volume
> cache. Increasing the daemons option gave the most improvement.
> The afsd man pages says that more than 6 daemons should not be needed,
> but my experiment seems to prove otherwise. What are the pros and cons
> of running with more alfsd daemons configured? Should the man page be
> updated to recommend running more daemons?
> What metrics can I use besides my applications run time to see that the
> client is optimized properly? xstat_fs_cache gives me so much data that
> it's confusing. How do I tell when increasing stat, volume, and daemons
> options would improve performance?