Re: Understanding problems with NFS & CVS.

[Paul Sander]

NFS is discouraged because there have traditionally been problems with
subtle incompatibilities between implementations, and it must also be
configured properly in order to maximize reliability.  Also, there have
been numerous reports of file corruptions taking place while writing
RCS archives over NFS, though I have not heard any lately on a properly
configured system.

To properly configure NFS, you must hard-mount the volumes (not soft-mount).
If there's an option to interrupt the NFS calls then enable that as well
(otherwise your clients become unresponsive to signals when the NFS server
hangs).

I have also personally experienced a problem with a major vendor's network
storage array where it would change "rename(a,b)" calls to "unlink(a)"
under load and fail to report an error.  This caused CVS to think it
successfully updated an RCS file, but then lose the update and keep the
old one.  This led to a fair amount of lost work and corrupt workspaces
(the workspaces were "more up-to-date" than the repository).  But this
happened probably 7 or 8 years ago and I'm sure it's fixed by now.

>--- Forwarded mail from address@hidden

>I fear I may have misunderstood the problems with NFS and CVS. As the two
>different threads in the archives on NFS didn't clarify the issue for me, I
>hope someone can clarify.

>I was under the impression that it was bad to share the CVS repository over
>NFS, so hence I have kept our repository on local disks in a machine that is
>accessed via SSH.

>For various reasons, I was queried why the repository is not placed on a NFS
>storage device, mounted on the CVS server which is then accessed via SSH. I
>quoted the NFS sharing problems, but the person retorted saying he has
>experienced large projects using NFS mounted on a frontend machine. Can
>anyone comment on the reliability of this? I don't understand why the
>problems would be any different simply by using a frontend machine. It's
>still NFS with whatever problems it carries with it.

>--- End of forwarded message from address@hidden