Dumping to an exabyte tape drive

[Frank P. Bresz]

In article <1990Aug29.143657.20588 at siesoft.co.uk> duncan at siesoft.co.uk (Duncan McEwan) writes:


>I'm not sure that this is the most appropriate group for this query, but I
>guess it will reach most of the people who will be able to answer it.

>I have just started using an exabyte tape drive to do dumps of our file
>systems.  Could someone please tell me the appropriate values to give
>to dump (tape length, density, inter-record gap (is this relevent for this
>encoding format?)) to allow dump to fully utilise each tape.

>For now I am kludging it using a bogus tape length of ~200000 feet (estimated
>by knowing that dump will write approx 64MB onto a 5400 ft streamer cartridge),
>but I would like to know the correct values.  In particular, how much *can*
>you fit on a single 90 minute tape, and how long are the tapes?

>I will summari[zs]e to this group any replies by email that aren't also posted
>here.

>Duncan

On A Sun I use :

dump 0ufsd /dev/nrst2 6000 54000 /dev/id000a

However I just got done dumping eleven partitions onto a single tape with
the following results:

  DUMP: estimated 8526 blocks (4.16MB) on 0.00 tape(s).
  DUMP: estimated 19870 blocks (9.70MB) on 0.01 tape(s).
  DUMP: estimated 59778 blocks (29.19MB) on 0.02 tape(s).
  DUMP: estimated 143480 blocks (70.06MB) on 0.06 tape(s).
  DUMP: estimated 179618 blocks (87.70MB) on 0.07 tape(s).
  DUMP: estimated 259772 blocks (126.84MB) on 0.10 tape(s).
  DUMP: estimated 395520 blocks (193.12MB) on 0.16 tape(s).
  DUMP: estimated 546268 blocks (266.73MB) on 0.21 tape(s).
  DUMP: estimated 748986 blocks (365.72MB) on 0.29 tape(s).
  DUMP: estimated 806824 blocks (393.96MB) on 0.32 tape(s).
  DUMP: estimated 895238 blocks (437.13MB) on 0.35 tape(s).

I checked the tape to see if it appeared valid and it did so I am stuck.
The MB totals total out to less than what is supposed to fit on a tape
2.3GB so I figured it was OK.  I would like to know also what settings are
appropriate.
--
Frank P. Bresz     | Westinghouse Electric Corporation                 \    /
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