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The /data folder was saved on tape with

dar -R /data/ -c - | mbuffer -R 110M -P 90 -m 1G | dd of=/dev/nst0 bs=256k

How can I test, list and extract it?

I tried the following to test the archive without luck:

# mt -f /dev/nst0 status
SCSI 2 tape drive:
File number=0, block number=0, partition=0.
Tape block size 0 bytes. Density code 0x58 (no translation).
Soft error count since last status=0
General status bits on (41010000):
 BOT ONLINE IM_REP_EN

# dd if=/dev/nst0 bs=256k | dar -t -
dd: error reading ‘/dev/nst0’: Cannot allocate memory
0+0 records in
0+0 records out
0 bytes (0 B) copied, 0.00344152 s, 0.0 kB/s
Opening a pair of pipes to read the archive, expecting dar_slave at the other ends...
�Final memory cleanup...
FATAL error, aborting operation
Corrupted data read on pipe
Jonas Stein
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  • you're forgetting a few things: a: set can be bigger than the tape size (dar split)
    b: if manual methods like this works for lto6- they can work thru lto2, perhaps lower.
    c: you are seeking the entire tape.
    What if multiple dar entries are present(do not rewind)?
    (more common than you think) -t for test, -l for list, -x for restore
    example above uses "test" write split tape:
    dar -c - | dar_split split_output /dev/tape read it back:
    dar_split split_input /dev/tape | dar -t - --sequential-read mind you- if youd rather debate people on tape vs disk and write     – someITalyman May 17 '19 at 00:19

1 Answers1

5

-0 for sequential read:

dd if=/dev/nst0 bs=256k | dar -0 -t -
Sathyajith Bhat
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Jerome Ibanes
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