Re: autofs no_local_binds option (nfs <-> bind mounts)

["H. Peter Anvin" <hpa@zytor.com>]

Eric Werme USG wrote:
> 
> The stop-gap cluster system in Tru64 Unix did this.  Typically pairs
> of servers had system names (service names in the jargon) and bound
> the IP address to a NIC on one server.  When the service was relocated
> manually or on a crash, the IP address was moved to a NIC on the other
> server.  Disks were on a shared SCSI bus, and the file system would also
> go through a umount/mount cycle.  Note that no changes to DNS' database
> are necessary, just an update to clients' arp tables.
> 
> For example, we have systems "mailhub1" and "mailhub2".  The service name
> "mailhub" is where Email here winds up.  I send mail via SMTP to mailhub, and
> read it via NFS from mailhub.  Normally I don't care which of mailhub1
> and mailhub2 handles it.  For the most part they're just servers, but
> sometimes there are reasons to login to one or both of those systems.

However, this doesn't address the issue of the client being *the same
system*, in which case you can't just move the IP address away from it,
since local == remote; you can no longer send packets to the server and
get a response back.  You can do it if you can get the client and the
server sides to bind to *different* IP addresses, in which case the
current autofs behaviour will correctly see them as being separate and
mount NFS.

	-hpa