Coda File System

Re: max venus cache size?

From: Jan Harkes <>
Date: Thu, 9 Sep 2004 12:08:18 -0400
On Thu, Sep 09, 2004 at 04:31:21AM -0500, Brian Finney wrote:
> curios what is considered to be the current max size for the venus cache

As far as the amount of data is concerned, probably about as much as
your harddrive can handle. The limiting factor is the number of files.
More files mean that we need more memory to store the metadata, we need
more CPU time to scan for possible replacements, and it takes longerto
revalidate the cache after a disconnection.

Now there is this estimated formula built into venus that assumes that
a typical user has an average file size of 24KB, about 4 files per
directory, 256 files in a volume, etc. So with the default ratios, the
cache probably shouldn't be larger than several hundred megabytes.
200MB is approximately 8000 files and requires only about 20MB of RVM.
I've heard several reports that 500MB caches (20000 files) can
sometimes suffer from considerable stalls, so memory doesn't really
seem to be the limiting factor here.

> I'm wanting to try coda starting with using it between my laptop and
> server, primarily for use with collections of movies, mp3s, and other
> files that would easily surpass these limits, and then if every thing

Your average filesize is several orders higher than our assumed
24KB/file. So it would make sense to tweak some of the values in

cacheblocks=10000000 # 10 GB cache
cachefiles=10000     # 10k files
cml_entries=40000    # 4 log entries per file.
hoard_entries=1000   # I 'think' this should be enough :)

(I really should change the cml_entries and hoard entries defaults to be
relative to the # of cachefiles and not the # of cacheblocks...)

Received on 2004-09-09 12:10:39