Coda File System

Re: directory searches in coda shared volumes and sizing questions

From: Jan Harkes <>
Date: Fri, 16 Jun 2000 13:15:38 -0400
On Thu, Jun 15, 2000 at 09:43:31PM -0400, Dr. Douglas C. MacKenzie wrote:
> files.  I assume this is due to the different directory structure
> I've seen mentioned impacting "find" commands.  I suspect
> the java commands do something similar to a find to get the

Unlikely, the find problem only occurs in directories that contain
mountpoints for Coda volumes. Since a Coda mountpoint is not really a
directory until the mountpoint is accessed and the volume get's
attached, the directory linkcount is off.

Find has some optimizations to avoid calling stat on the directory
entries once linkcount-2 directories have been seen. This way the
mounted Coda volumes confuse these optimizations and whole subtrees are
never traversed.

> How big of coda partitions are people using?
> I set up a 1.1Gig data partition,  44Meg rvm partition,
> and a 2Meg log partition and it seems to be working OK
> on a 266 PII machine with 64Meg of memory and a
> 64Meg swap partition.

We have about 120MB RVM for a 2GB server, but are not yet sure how much
of that RVM is really in use (at least we haven't run out of RVM on that
machine yet).

> Unfortunately, 1 Gig doesn't go very far anymore so I'm
> looking at the 3.3Gig setup.  Is it OK to allocate more
> rvm data than the size of physical memory, as long as
> real+swap < rvm or do I need to add more memory?

Yes, one machine has 128MB memory but has no problems mapping 330MB of
RVM data.

> If I add a second server, are the data partion sizes additive,
> or am I still limited to a 3.3Gig total coda filespace across
> the cluster?  I'd like to get to around 10Gig total.

10GB should be doable even with one server, the sizes are only additive
if you do not use any doubly replicated volumes. If everything is singly
replicated you can add the disksizes.

If everything is doubly replicated, there is the advantage that when one
server is lost, it is simple to reinitialize it, recreate the lost
volume replicas, and then resolve the whole tree back by doing ls -lR.
But in that case you can't add the sizes anymore.

Received on 2000-06-16 13:17:08