Hi David,
I have some experience with AFS RAM cache on an
IBM RISC System/6000 model 990 (yes that long ago! ;-)
with AFS 3.3 and AIX 3.2.
This 990 had 1 GB of RAM and I tried using a 128 MB
AFS RAM cache.
It worked pretty well. It was especially good when
compiling larger (eg lots of .c files) C programs.
Once the accessed files were cached, subsequent
re-compilations really "flew" (by comparison to
a disk cache setup). It was also worth "priming"
the RAM cache with something like:
cd $src; tar cf - . > /dev/null
I was advised by Transarc support that RAM caches
use up far more memory than you might expect.
AIX itself does a certain amount of RAM caching
of file access (eg from /usr/vice/cache to RAM).
Despite that, and running on a busy multi-user machine
there was a definite improvement of file access.
If I had enough memory (eg at least 256 mb), I would
use a RAM cache (eg 64 mb on 256).
--
cheers
paul http://acm.org/~mpb
"WARNING: Objects in the network may appear closer
than they really are."
