Coda File System

Re: R: coda + reiserfs

From: Jan Harkes <>
Date: Thu, 19 Jul 2001 10:05:26 -0400
On Thu, Jul 19, 2001 at 03:47:45PM +0200, Andrea Cerrito wrote:
> Of course, reiserfs is great, but do you need his advantages in a coda env?
> I mean, dealing with speed, transimitting data over the network is always
> slower then a local fs (reiser/ext3/ext2). So I think the needed feature is
> just journaling for data integrity, and this can be done with the simplier
> ext3.

The only need for speed would be when the file is already cached on the
client and doesn't have to come across the network. Coda places cached
files in an hierarchical directory tree to minimize the effect of slow
linear directory lookups by never having more than 256 entries in a
directory. We need 4 directory lookups to find any specific container
file, but each lookup only compares on average 128 entries instead of
cached-files / 2 compares.

Currently, Coda shouldn't really see any improvement with the more
advanced btree based directories that reiserfs provides, in fact the
additional overhead to keep the tree balanced will probably only give a

Perhaps it would be advantageous to have a config option to actually use
to a flat venus.cache layout for filesystems that don't have O(n)
complexity for directory lookups/operations.

Received on 2001-07-19 10:05:41