Re: Hardware advice: seeking echoes of running Linux-PC clusters

[bruce@pixar.com (Bruce Perens)]

> If I remember
> correctly, the current version of dpkg doesn't support installing with
> a read-only /usr.

/usr must be mounted for write while software is being installed on it,
but it may be read-only at all other times. And of course software need
only be installed on the master system.

The root filesystem and the /var directory tree should be replicated for
each system. Actually, everything but /etc and /var can be shared, and you'll
probably want to do this if there is no local disk at all.

You would need to keep a copy of a "prototype" root and /var, so that when
packages installed files you could tell (using diff -r) if files in root and
/var had changed, and you could then replicate those files on the client
systems (using "dist", perhaps).

Directly booting with the root on NFS is possible with a correctly-configured
1.3.9x kernel. I've not tried it. I would strongly recommend that all systems
have a local swap disk, as you tie up your network with virtual memory paging
if you don't have one.

	Thanks

	Bruce