Backing up LMFS on Sun

[Barry Margolin <barmar@THINK.COM>]

    Date: Wed, 20 Sep 89 15:44:23 EDT
    From: charles@nynexst.com (Charles Jankowski)

    With all of this talk about mounting LMFSs on LMFSs and such,
    does anyone know what kind of dumping software exists out there
    for the Sun (we have a 4/280 running 4.0.1 and soon 4.0.3)
    that will dump mounted filesystems over the net? I want to
    be able to dump my Symbolics on an Exabyte. If such software
    exists, any idea how slow this process is?

I've heard that GNU Tar has enough features to be useful as a
backup/restore facility, and I expect that it uses generic file I/O so
it should work with NFS file systems.

Lispms are relatively slow NFS servers.  They have to spend lots of time
translating Lispm user names to Unix userids; they cache the results, so
they speed up over time, but it's pretty noticeable.  And there's lots
of overhead in the Lispm network software.  I wouldn't be surprised if
dumping a LMFS were an order of magnitude slower than dumping a Sun file
server in that way.

Another alternative would be to run an RTAPE server on the Sun, using
the LMFS dumping software to send to the Sun's Exabyte tape drive.  This
requires that the Exabyte can be accessed using the standard mtio
driver.  I'm working on getting our Unix TCP RTAPE server working on the
Sun.

                                                barmar