>
> > > - Netapps are impossible to back up
> > Not so. There are many ways to backup a filer. The fasted by far is
> > direct attached SCSI though. If investing in large filers, one might
> > consider the use of DLT for backups.
Interestingly, there was brief discussion on toasters a few weeks ago
about slow backups to a local SCSI tape, when the drive was made remote
the backups went MUCH faster. It seems that the additional buffering
provided by the network allowed the tape drive to stream better than
when it was attached locally.
> In a larger environment you probably don't want to backup each
> fileserver separately with an attached DLT. And as NetApp doesn't
> support a reasonable NDMP version which allows backup over the net the
> only way to do a central backup is through NFS - not a very smart
> solution.
Hmmm, we've been using the native dump to a remote tape (DLT and 3590)
using rmt protocol, we have found that we get good transfer rates (with
100Mbit and FDDI the drive streams nicely). We can restore the data using
standard Unix restore (AIX and Solaris). In fact just to test our backups
we routinely restore 2 Gig sections from dumps, we do other tests involving
selecting a number of files at (pseudo)random and restoring them, then
comparing them with the original data (first testing to see of the file
has been modified since it was dumped).
Clearly this is NOT backing up through NFS. We've been doing this for
several years now, before we integrated it into our standard backup scheme
(home grown, we backup filesystems from a wide range of unix systems) we had
a set of scripts that were run by cron to back the filers up using
knowledge of the sizes of the filesystems to ensure that any one piece
would fit on a tape.
Something to the effect of (our tapes are attached to stackers which
load the next tape automaticly):
rsh filer dump <level>ufbB <host>:<device> 32 35000000 filesys1
rsh filer dump <level>ufbB <host>:<device> 32 35000000 filesys2
rsh filer dump <level>ufbB <host>:<device> 32 35000000 filesys3
rsh filer dump <level>ufbB <host>:<device> 32 35000000 filesys4
rsh <host> mt -f <device> rewoffl;
rsh filer dump <level>ufbB <host>:<device> 32 35000000 filesys5
rsh filer2 dump <level>ufbB <host>:<device> 32 35000000 filesys6
rsh filer2 dump <level>ufbB <host>:<device> 32 35000000 filesys7
rsh <host> mt -f <device> rewoffl
rsh filer3 dump <level>ufbB <host>:<device> 32 35000000 filesys8
rsh <host> mt -f <device> rewoffl
Clearly this produces reasonable backup volumes and is quite straight
forward. If your filesystems are larger than will fit on a single
tape, you have to be a little more creative (using expect to fake
interaction), or run the backup interactively.
-----
Stephen C. Woods; UCLA SEASnet; 2567 Boelter hall; LA CA 90095; (310)-825-8614
Finger for public key scw(a)cirrus.seas.ucla.edu,Internet mail:scw@SEAS.UCLA.EDU