[comp.unix.admin] Exebyte drives / networking

jordan@unix.cis.pitt.edu (Kenneth D Jordan) (06/21/91)

We're interested in attaching an Exebyte tape drive to an IRIS (which
already has a SCSI interface).  Aside from local activities originating
on the IRIS, we plan to do archiving from a FPS Model 500EA (running FPX
4.3.2, FPS's port of BSD 4.3).  Here's a summary of the configuration:

        +---------+   Ethernet   +---------+   SCSI   +---------+
        | FPS 500 +--------------+ SG Iris +----------+ Exebyte |
        +----+----+              +----+----+          +---------+
             |                        |
        +----+----+              +----+----+
        |  Large  |              |  Small  |
        |  Disks  |              |  Disks  |
        +---------+              +---------+

Certain files on the FPS are larger than the maximum amount of disk
space on the IRIS, so archives can't be done by copying the file to
the IRIS and then dumping it to tape.  Ideally a process on the IRIS
would pipe input from the network to the IRIS's tape driver.

Is anyone doing something like this?  How?
Does BRU solve any of the problems of doing backups over a network?

-----------------------------------------------------------
Nick Nystrom   University of Pittsburgh   nystrom@a.psc.edu
-----------------------------------------------------------

-- 
       ---------------------------------------------------------------
        Nick Nystrom    University of Pittsburgh    nystrom@a.psc.edu
       ---------------------------------------------------------------

olson@anchor.esd.sgi.com (Dave Olson) (06/23/91)

In <142379@unix.cis.pitt.edu> jordan@unix.cis.pitt.edu (Kenneth D Jordan) writes:

| We're interested in attaching an Exebyte tape drive to an IRIS (which
| already has a SCSI interface).  Aside from local activities originating
| on the IRIS, we plan to do archiving from a FPS Model 500EA (running FPX
| 4.3.2, FPS's port of BSD 4.3).  Here's a summary of the configuration:
	(omitted)
| Certain files on the FPS are larger than the maximum amount of disk
| space on the IRIS, so archives can't be done by copying the file to
| the IRIS and then dumping it to tape.  Ideally a process on the IRIS
| would pipe input from the network to the IRIS's tape driver.
| 
| Is anyone doing something like this?  How?
| Does BRU solve any of the problems of doing backups over a network?

Well, assuming that the FPS supports the "standard" remote tape
interface, then you could just use that, since SGI has /etc/rmt.
Syntax is usually something like:
	bru options -f user@mach:/dev/device files

You could also do an 'rsh irismachine bstream yourparams' which should be
somewhat more efficient than the more common 'rsh irismachine dd yourparams'
since the network and tape interface i/o get overlapped.  On a lightly
loaded network you should be able to get pretty close to the exabyte
maximum rate (240Kb/sec) with this method, assuming the writer on the FPS
runs that fast.

Finally, if both systems have NFS, mounting the FPS disks onto the
Iris and just running bru on the IRIS would be a viable option.