Coda File System

Re: Released Coda 6.0.3 (and RPC2 1.20)

From: Jan Harkes <jaharkes_at_cs.cmu.edu>
Date: Wed, 14 Jan 2004 17:23:49 -0500
On Wed, Jan 14, 2004 at 09:18:47AM -0500, Greg Troxel wrote:
>   > > === soon to be merged in CVS, this is NOT in 6.0.3! ===
>   > 
>   > >     Coda servers use a vnode lookup table that is causing some 'growing
>   > >     pains' for larger servers. The re-allocation of such a table would
>   > >     fail when we reached around 100k files per volume. These tables will
>   > >     be replaced by a hash table which with moderate success allowed us
>   > >     to store about a million files in a single volume. This does require
>   > >     some incompatible RVM changes to the vnode structure.
>   > >
>   > >     As we're going to be breaking the vnode structure anyways, we will
>   > >     take the opportunity to move the per file SHA1 checksum into RVM.
>   > >     This should significantly reduce server CPU usage when checksums
>   > >     are enabled.
> 
> 
> I note that there is no NEWS file in cvs for coda, and the Changelog
> doesn't mention this yet.  Has CVS coda been changed in an
> incompatible way.

No, it is still a bit too experimental for now. There are still problems
when resizing the hashtable and volume cloning/backups are possibly
broken as a result of these changes.

And we have several hundred volumes on our own production servers, so
any change of this significance will definitely be done only if we can
be 100% sure that everything is going to be allright, and that there is
a valid way of switching back to the old servers just in case it isn't
working well enough.

Right now CVS contains mostly bugfixes, there are still a couple of
minor ones that I have lying around (I think I just found the
MAXNAMELEN/MAXPATHLEN problem).

I guess I can say that 6.0.4 will be 6.0.3 with annoying bugs fixed. If
we make any significant change we'll call it 6.1 or something and brag a
lot about it.

> Perhaps this is happening, but I don't feel confident that I'm not
> going to lose by using CVS.
> (And since I'm losing with 'local inconsistent objects' today, I am
> inclined to upgrade.)

There are CVS-commit mailinglists (changelog(at)coda.cs.cmu.edu and
cvs(at)coda.cs.cmu.edu), the difference is that 'changelog' only has the
commit message, while the 'cvs' one includes the diff of the committed
changes. They work like codalist, so subscribe messages would go to
cvs-request(at)coda.cs.cmu.edu.

I do try to keep the commit messages useful as I use them as a reference
for the announcements and NEWS/ChangeLog files in the distributed
source tarballs.

Jan
Received on 2004-01-14 17:26:05