[TUHS] /bin vs /sbin

[Kurt H Maier]

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