[OpenAFS] Tuning the -daemons.

Jan Johansson janj@it.su.se
Mon, 7 Feb 2011 16:53:25 +0100


Short version:

How do I see how many of the "background daemons" that are in use?

Long version:

We have a pretty busy IMAP server with Maildir's in AFS (yeah its
probably crazy but we have been doing it for a number of years).

On an untuned Ubuntu with 5 users we saw an issue where the cache
manager would freeze and start reporting 

afs: Lost contact with file server AAA.BBB.CCC.133 in cell example.com

at the same time the file server reports

fileserver[1139]: CB: Call back connect back failed (in break
delayed) for Host AAA.BBB.CCC.186:7001

fileserver[1139]: BreakDelayedCallbacks FAILED for host
AAA.BBB.CCC.186:7001 which IS UP.  Connection from
AAA.BBB.CCC.186:7001.  Possible network or routing failure.

sometimes it recovers after a while other times it needs a

Looking at the man page I started by setting "-daemons 6" this
has allowed us to accept 15 users with no problems at all, but
the real number in production will probably be more like 250

Googling around I have found both "-daemons 8" and "-daemons 16"
so to tune this properly I wounder "How do I see the number of
daemons currently in use?"

(I am certain that I will need to tune other values but this
seemed like the simple place to start.)

Jan J