[776] in Info-AFS_Redistribution
Re: cache parameter question
daemon@ATHENA.MIT.EDU (Peter Lister, Cranfield Computer C)
Mon May 18 06:27:13 1992
To: bob_dew@alw.nih.gov
Cc: ccprl@xdm001.ccc.cranfield.ac.uk, info-afs@transarc.com
In-Reply-To: Your message of Sat, 16 May 92 00:34:21 +0100.
Date: Mon, 18 May 92 09:42:12 BST
From: "Peter Lister, Cranfield Computer Centre" <ccprl@xdm001.ccc.cranfield.ac.uk>
Bob,
If you have a slow network link, you need to reduce chunksize. Most clients
here use the default 2^16 which is fine forlocal Ethernet access, but we have a
slow (19.2kbaud) link to the rest of the world; operations on files over about
32K (it depends on other network usage) fail with "Connection timed out"; chunk
transfers still work, but time out before completion. On Transarc's advice, I
dropped the chunksize of some clients to 2^14, and the problem went away.
Another question: If I drop the chunksize of all clients to 2^14, what effect
would this have on access to local files via Ethernet?
Presumably network traffic will increase, but:
* Will access to large files be significantly slower?
* How will caching behaviour change?
* How will the servers react?
I honestly haven't noticed much change on the one or two machines where
I tried this, but reducing the chunksize on all 90 clients and servers
is a big step, and I'm inclined NOT to do so until I have a better idea
what might happen.
Peter Lister p.lister@cranfield.ac.uk
Computer Centre,
Cranfield Institute of Technology, Voice: +44 234 750111 ext 3157
Cranfield, Bedfordshire MK43 0AL England Fax: +44 234 750875
