On Tue, Jul 21, 2020 at 09:44:31PM -0400, Dan Cross wrote:
When I first came on the scene, there was a convention that I thought
worked well: the "dataless" node. I have no idea why it was called that; I
suppose because most interesting data was on a centrally managed file
server. Anyway, this was under SunOS 4: the idea was that each node had a
small disk; enough to hold / and swap, but mounted /usr, /usr/local and
user directories from a file server. So commonly used stuff (/bin/csh, ls,
etc etc) all came from a local disk, while everything else was shared.
Disks in workstations were small and basically turn-key so that we didn't
back them up: if one crashed, oh well: throw a new one in it and reimage /.
Swap was transient anyway. A variation was to have an owning-user's home
directory on the node if the local disk was big enough. Sometimes there'd
be a /scratch partition for bulk storage that persisted across reboots
(/tmp came from tmpfs and was a swap-backed RAM disk). We'd back up local
home dirs and maybe the scratch directories.
In our network, we used `amd` and NIS (YP!) to get access to everyone's
home dir on every node.
I rather liked the overall setup; it was nice. It became a deprecated
configuration on the move to Solaris 2.x: a workstation was either diskfull
or diskless. The idea of a compromise between the two extremes went away.
- Dan C.
This is how we run our clusters, but instead of NFS-mounting the system
directories, it fetches a cpio archive and unpacks it into a RAM disk,
then switches root to that. Any local disk is mounted as scratch space,
home directories come from an NFS server, and the main working
filesystem is a high-performance distributed filesystem. It works
exceptionally well at the cost of whatever RAM is used to store the root
filesystem -- these days, negligible. AFS is available but not much
engaged by our users. Everything boots over PXE and entirely changing
the purpose and loadout of a computer is one or two commands away. It's
very pleasant.
khm