Subject: performance problem

From: Brent Dunlock <[email-masked]>
Date: Fri, 13 Jan 1995 08:20:35 -0700

We have a Sparc-20 running Netatalk 1.3.1 with AFS, disk cache turn on (about
200MB of it), and standard configuration for SunOS 4.1.3_U1.  This system runs
only Netatalk.  The problem we're seeing is that after about 45-50 user get on,
the repsone time at the MAC's gets really bad.  The other traffic on this
ethernet segment is reasonable, so I would think that a Sparc-20 would be able
to handle a lot more users than that...

Looking at vmstat and iostat it seems like the cpu is about 40% idle and we
have plenty of memory (256MB).  I/O seems ok and I don't think it's AFS since
the major applications that are being accessed are local copies (i.e.
replicated volumes in AFS).  So, I'm wondering if there are any tuning things
etc., that I might try to get better performance out of this box.

Any suggestions?  Or, specifically, are there any tuning knobs in Netatalk I
can twist?

---

From: [email-masked]
Date: Fri, 13 Jan 1995 15:54:04 -0500

> From:    Brent Dunlock <[email-masked]>
> To:      [email-masked]

> We have a Sparc-20 running Netatalk 1.3.1 with AFS, disk cache turn on
> (about 200MB of it), and standard configuration for SunOS 4.1.3_U1.
> This system runs only Netatalk.  The problem we're seeing is that after
> about 45-50 user get on, the repsone time at the MAC's gets really
> bad.

> Looking at vmstat and iostat it seems like the cpu is about 40% idle
> and we have plenty of memory (256MB).  I/O seems ok and I don't think
> it's AFS since the major applications that are being accessed are local
> copies (i.e.  replicated volumes in AFS).

I'd say your problem is AFS.  Try copying your replicated AFS volumes
to local disk space.  I'd bet your problems disappear.  In my
experience, even when an AFS file is cached on the local disk, it takes
considerably longer to access than local disk space.  Also, do you have
cache hit rate ratios for AFS?  The only other suggestion I can make is
use a sniffer to pin-point the bottle-necks.

There may be things you can do to tune AFS for netatalk.  There's very
little you can do to tune netatalk for AFS.

:wes

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From: "Matthew V. J. Whalen" <[email-masked]>
Date: Fri, 13 Jan 1995 16:39:20 -0500

>little you can do to tune netatalk for AFS.

I found that decreasing the chunk size helped a lot since there are all those
small pesky files (ie - appledouble).

-matthew                 ____         "Thanks mom...
[email-masked]    \  /         love the genes."
Voice:(703)708-1621       \/          #include <std/disclaimer.h>