Coda File System

Re: Usage problems.

From: <>
Date: Tue, 17 Feb 2009 09:06:03 +0100
Hi Grzegorz,

On Mon, Feb 16, 2009 at 09:17:25PM +0100, Grzegorz Nowakowski wrote:
> there is /home/$user volume, and only the latter is used for data
> storage now.

> 1. What is practical maximum volume size, in terms of used space and
> number of files?

It depends on the usage pattern. A volume is a unit of serialisation.
Otherwise see

> 2. What is practical maximum file size to be pushed around?

It depends on your network and your patience.
(Otherwise see

> Use case: I have already learned that Coda isn't good choice for filer
> with size of hundred gigabytes.  I have settled for my /home/$user.  It's

Note that the file size is limited to 2G.

> about 1,5GB and has about 30k files.  Yet even with this amount of data
> venus tends to eat more than 80% CPU, clog the system and become totally

I guess this is due to your use of hoarding. Hoarding does not scale well
as it is implemented now. I am not using it so can not help you with this.

> 4. Is it possible to verify cache contents?  That is, to determine
> whether given file/directory is viewed remotely or is taken from local
> cache?

Any file you are viewing from Coda is copied to the local cache at the time
of open() system call.

> Also, I haven't got success with opposite operation: purging cache (to
> save some filesystem space).

You should always have the space for your cache reserved on the disk.
Do not overbook, you will regret.

> 5. How can I instruct venus to forget realms?

No way besides client reinit.

> From here on there are no actual problems.  More like random ideas.

I guess you find some discussions of similar ideas if you look in the list

> 7. Is it possible to set per-volume quota?  Like the hard limit on
> volume size?  AFAIK there is only per-user quota which sometimes is not
> enough.

The other way around: there is volume quota only, no user quota.

> It's really good
> piece of work which I'm sure I couldn't do better in reasonable time.

:-) you may find an estimation of what "a reasonable time" for Coda is

> Yet the problems are annoying and I can't even use alternative because
> there doesn't exist any!  I haven't found another remote filesystem with
> persistent local cache, with the ability to work disconnected.

There isn't any, just because it _is_ hard to do right.

So if you can live with what Coda looks like now and want to make it better,
join the development. This is not for the faint-hearted, improvements
postulate deep understanding of the concepts and of the code, but may be
you will find this challenge exciting.

Best regards,
Received on 2009-02-17 03:07:16