W0L@psuvm.psu.edu (Bill Lasher) (11/15/90)
We have an environment with a large number of users (~400) on a group of machines. I am looking for a simple way for these people to archive files. We have 1/4" cartridge tapes, and tar (or bru) won't allow you to append archives. The result is the users have lots of tapes with small files on them. Any suggestions that won't require the users (they are students) to buy *REAL* expensive tapes? Bill P.S. Floppy drives won't do it; some of the files are too large (up to 20M).
blbates@AERO4.LARC.NASA.GOV ("Brent L. Bates AAD/TAB MS361 x42854") (11/16/90)
So buy some MO drives. Magneto-Optical disks are removable and can store about 300Mb/side. You would use them like you would a regular magnetic disk, directories and all. On second thought that might be too expensive. The last firm price I heard for MO disks was about $200 each, however, I have heard rumors of them being down to $100 each now, but nothing firm. -- Brent L. Bates NASA-Langley Research Center M.S. 361 Hampton, Virginia 23665-5225 (804) 864-2854 E-mail: blbates@aero4.larc.nasa.gov or blbates@aero8.larc.nasa.gov
architec@cutmcvax.cs.curtin.edu.au (Phil Dench ) (11/16/90)
W0L@psuvm.psu.edu (Bill Lasher) writes: >We have an environment with a large number of users (~400) on a group of >machines. I am looking for a simple way for these people to archive files. >We have 1/4" cartridge tapes, and tar (or bru) won't allow you to append >archives. The result is the users have lots of tapes with small files on them. >Any suggestions that won't require the users (they are students) to buy *REAL* >expensive tapes? >Bill I asked the same question myself several months ago. This is the most helpfull reply I received from Dave Olson. > If you can accept multiple archives on the tape, then this sequence will > work. If you keep track of the archive number, you can use mt fsf # to > space to the one you want to list or extract from. > Unfortunately, there is a bug in the 3.2 tape driver that causes this > sequence to not work reliably for all drives; when it doesn't work, the > first archive can be overwritten. So if the 'mt status' doesn't show > EOD, then don't do the tar cv! > first archive: tar cv .... > 2nd thru N: mt feom; mt status; tar cv ... > listing, you can do: > tar vtf /dev/nrtape; tar vtf /dev/nrtape; tar vtf /dev/nrtape; ... > or > mt fsf N; tar vt > If you don't specify the nrtape device, it will rewind at the end, but it > will NOT rewind or reposition before writing if you are at BOT, FM, or EOD. > Hope this helps. > Dave Olson ... and make sure you do the 'mt status'. Phil
kcables@RELAY.NSWC.NAVY.MIL (12/03/90)
Hi everyone. I'm trying to write a script to do incremental
backups on an 8mm cartridge. What I'd like to do is create multiple
archives on the same volume, i.e., start at the beginning of the
cartridge for Monday's archive, append Tuesday's archive to Monday's, etc.
The man page for tar says that the -r (no rewind) option only works for the
9 track tape, so I'm assuming I can't use tar for this purpose with an
8mm cartridge, or even if there is a way to use tar the SA book says
it's unreliable. The System Admin class book, in the chapter "Backups",
says that multiple archives are possible, and they recommend using bru
(p. 15). Unfortunately, they don't explain the semantics. So
then I tried bru, whose man page doesn't say anything about multiple
archives, only multiple volumes. With bru you must specify one of the
mode options, and the only one that instructs bru to actually write
to the tape is -c ("create a new archive"). According to the man page,
-c causes the writing to start at the first block, which I'm not
sure means at the very first block of the cartridge, or at the
beginning of the next full block (i.e., it skips any remainder of the
current block).
'tape8' and 'tape8nr' are symbolic links to the cartridge tape drive.
This is what I tried:
find <files to save> | bru -cvd -f /dev/tape8 -
which works fine for the first archive.
Then I tried:
find <other files to save> | bru -cvd -f /dev/tape8nr -
and it responded with
bru: warning - assuming end of volume 1 (unknown size)
bru: load volume 2 and enter device [default: /dev/tape8nr] >>
What am I missing here? Thanks in advance.
My address is kcables@relay.nswc.navy.milscotth@corp.sgi.com (Scott Henry) (12/04/90)
I have been successfuly putting multiple archives on one 8mm (Exabyte)
tape for several months. I have been using it to do (3x/week) backups of
the machines in my group. The following is extracted from the scripts that
I run to do my backups. It has been working without fail since June with
all the releases and alphas I've run of 3.3, 3.3.1 and 3.3.2.
mt -t $tapedevice feom
(versions -cm ; find ${where} ! -type d -mount -depth -print) |\
tar -cbf 128k $tapedevice -
where $tapedevice is the approriate no-rewind tape device on either the
local or remote system, and $where expands to a list of directories to
backup.
-- scott
--
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