Coda File System

Re: Cache Overflow

From: Jan Harkes <>
Date: Wed, 11 Aug 1999 18:51:08 -0400
On Wed, Aug 11, 1999 at 03:16:15PM -0400, wrote:
> Hi! I just set up a server (FreeBSD 3.1) and two clients (FreeBSD 2.2.8)
> that I was hoping to be able to use for large (>2GB files). However, my
> first problem is that when I try to work with files over the client cache
> size (20MB), the client spits out every 30 sec:

Hi Rob,

Coda uses `whole file caching'. So your cache needs to be (at least) as
large as the 2GB file you are trying to work with. And, as you might
have noticed, the cache-limit is a little `soft', and Coda only
complains once every 30 seconds about an overflow, and you might want to
have the directories leading up to the file cached so it is probably
better to have a larger local cache size.

Also, when you are making changing while disconnected, the client
`saves' the modification logs to the local disk, so that you won't lose
those important papers when the client crashes (that is another 4GB on
the local disk).

So with a 6-10 disk and 2-4GB cache you would be fine. And because you
have (on average) very large files, we wrongly allocate way to many
filesystem object/container files when you start venus for a 4GB cache.
And that results in a very large/slow beast. You really need to override
the estimated number of fso's by passing the -cf flag on the venus

Reinitializing RVM by starting venus as: 'venus -init -cf 500 -c 4194304'
should do the job for you.

> The other client can't even read the file anymore. All 3 are using the
> precompiled packages from Can someone tell me what
> went wrong? Thx!

Too big for the cache. The limit is soft in some ways, as we can only
account for the filesize when it is closed by the last writer. But very
hard in others, when there is not enough cachespace, and we cannot throw
anything else out, you are not allowed to fetch more data.

Let me know how it works with those commandline flags. btw. You only
need to specify them the first time you start, venus will from then on
read the settings from the initialized RVM data.

> 								-Rob H.

Received on 1999-08-11 18:51:53