[OpenAFS] Tuning openafs write speed

Kai Moritz Kai.M.Moritz@gmx.de
Thu, 23 Aug 2007 11:13:44 +0200

Hi folks!

I would like to try tuning the speed of my openafs installation, but the only information I could google is this rather old thread
(http://www.openafs.org/pipermail/openafs-info/2003-June/009753.html) and the hint to use a big cache-partition.

For comparison I've created files with random data and different size (1MB, 2MB, 4MB, 8MB, 16MB, 32MB, 64MB and 128MB) on my local disk.
I copied them into AFS and then I copied then to the same disk on the same host via scp (without compression). I've done that 10 times and computed the average.
For the 1MB file AFS ist slightly faster then scp (factor 0,89). For the 2 and the 4MB file AFS needs about 1,4 of the time scp needs. For the 8, 16 and 32MB the factor is about 2,7 and for the 64 and the 128MB file it is about 3,3.
I've already tried bigger cache-partitions, but it does not make a difference. Are there tuning parameters, which tell the system a threshold for the size of files, beyond which data won't be written to the cache?

Greetings Kai Moritz
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