[OpenAFS] Disk Based Or Memory Based Cache

[Derek Atkins]

Hi,

Lan Zhang <chz@mercury.cs.wayne.edu> writes:

> Hello,
> 
> Which kind of cache do you recommend? Disk based or memory based? Is there
> an upper limit of the meory besed cache?

Well, it very much depends what you want the cache for.  The disk cache
is a bit slower than the memory cache, but it's persistent across reboots.
Also, the disk cache can generally be much larger than a memory cache.

> The applications people usually run are : matlab, mathmetica, netscape,
> mozilla, maple, avs, idl, staroffice, etc. We use solaris 8, openafs
> 1.2.9.

These are rather large apps.  The memory cache uses non-pageable ram,
so if you want a reasonable size memory cache you'll need an extremely
large amount of ram.  For example, I run with a 3GB disk cache on my 
laptop; there is no way I could have a 3GB memory cache...  Even though
I've got 1GB RAM I'd be hard pressed to run with a 250MB Memory Cache.

> Thanks a lot.
> 
> Zhang Lan

-derek

-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
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