Coda File System

Re: Coda project needs - documentation

From: Ivan Popov <>
Date: Sat, 9 Apr 2005 12:26:49 +0200
Hi Patrick,

On Fri, Apr 08, 2005 at 04:07:14PM -0600, Patrick Walsh wrote:
> 	When I create groups I specify an owner and I thought (wrongly) that
> acls were done on a per-volume basis.  

No, they are per-directory.

> 	I think what you're saying is that you can apply unix permissions to
> files, but that's useless, you have to stick with coda acls to deal with
> group and user permissions, correct?


> Or can acl's be circumvented with a modified client?

No. They are checked against on the server.

> 	Again, coda groups can have rights to directories, they just don't mesh
> with unix-style permissions and ownership, correct?


Be aware that if some program or user resets the "owner access bits",
it will prevent _any_ party to access the file (it is per-file)
It is a deliberate "feature" which does not really protect from anything,
but sometimes may protect the user from herself...

With other words, ignore all "access bits" but do not reset "user bits"
to zero as then you get a different and controversial semantics.

> > the client a lot more RVM-hungry than the server for the same amount of data
> > (number of files and directories, which on the other side is usually a lot
> > higher on a server than on a client)
> 	Huh.  Very interesting.  What happens if you run into this limit?  Can

Venus does not start if it tries to allocate more than 1Gb RVM at the beginning.
Client may crash if RVM becomes full - I never seen that.

> you calculate it somehow?  Like by adding max hoard files in venus.conf
> and then figuring on a certain amount of RVM per file?  Or do the diffs
> reside in RVM?  This has a big impact on how I allocate RVM and cache
> size on my clients and I'd like to understand it a bit better (even
> though I don't expect much disconnected writing to occur).

I think Jan commented on that once, I do not have the figures at hand.
Try to look in the archive. I know it is not easy... :)

> 	When I've got the above clarified I'll send out a new draft.


Received on 2005-04-09 06:28:36