Using Ultrium 7 WORM tapes

[stevemowbray]

tar -xvf will extract files. The man page would definitely be a help

[tunk]

As suggested, use tar -xvf: x=extract, t=list.
And I seem to remember that it will extract to the current path, i.e. make sure you don't overwrite something important.

[badgerfruit]

As suggested, use tar -xvf: x=extract, t=list.
And I seem to remember that it will extract to the current path, i.e. make sure you don't overwrite something important.

#SchoolboyError

Yep, correct ... using tar xf worked and yes, extracted into the current working directory.
Guys, thank you for your help, you won't believe how much hair I have lost with this the past few days and weeks!!

ps, Yes, I discovered this for myself using the man page

[badgerfruit]

Hello,
I'm sorry to bump this thread but since I last posted I have been on other projects and just returned to this now.
So, after all the help received last time (thank you all!), I was hoping to pick more brains to figure out how I can write multiple tar's to a WORM tape.

I used the command below to write some data to the tape:

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tar -c /mnt/bigdisk/quantum-backup | mbuffer -t -m 2048M -P 80 -o /dev/st0

And when I do the command below, I see it's worked:

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dd if=/dev/st0 bs=1M | tar -tvf -

drwxr-xr-x root/root         0 2018-02-15 11:49 mnt/bigdisk/quantum-backup/
-rw-r--r-- root/root     12288 2018-01-19 11:37 mnt/bigdisk/quantum-backup/.oldbackup.old.swp
drwxr-xr-x root/root         0 2018-10-29 15:51 mnt/bigdisk/quantum-backup/templates/
-rw-r--r-- root/root       185 2018-02-15 13:04 mnt/bigdisk/quantum-backup/templates/tapebackupfailed.txt
-rw-r--r-- root/root       210 2018-02-15 13:04 mnt/bigdisk/quantum-backup/templates/tapebackupcomplete.txt
-rw-r--r-- root/root       202 2018-02-15 13:03 mnt/bigdisk/quantum-backup/templates/tapereminder.txt
drwxr-xr-x root/root         0 2018-12-04 00:19 mnt/bigdisk/quantum-backup/data/
-rwxr-xr-x root/root      4639 2016-12-29 09:27 mnt/bigdisk/quantum-backup/data/tf-insite.php
-rwxr-xr-x root/root  51604992 2018-12-04 00:01 mnt/bigdisk/quantum-backup/data/Patbase.adp
-rwxr-xr-x root/root  29118976 2018-12-04 00:01 mnt/bigdisk/quantum-backup/data/Patbase.ade
0+13135 records in
0+13134 records out
53796864 bytes (54 MB) copied, 2.20562 s, 24.4 MB/s

However, as this is to help me create a backup script, I want to append more data to the "end" of this write rather than trash WORM 7 6TB tapes (at £70+ per shot!) with a single, 3gb write!!

I have google'd the shazam out of this and seen many sites with useful tips but none work, for example using:

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mt -f /dev/st0 rewind
mt -f /dev/st0 asf 2

and then performing the tar again (trying to use a different folder), like below, gives an error:

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mt -f /dev/st0 rewind
mt -f /dev/st0 fsf 1
tar -c /tmp | mbuffer -t -m 2048M -P 80 -o /dev/st0
tar: Removing leading `/' from member names
in @  0.0 KiB/s, out @  0.0 KiB/s,  0.0 KiB total, buffer 100% fullmbuffer: error: outputThread: error writing to /dev/st0 at offset 0x0: Input/output error
in @  0.0 KiB/s, out @  0.0 KiB/s, 0 x  0.0 KiB total, buffer 100% fullmbuffer: error: error closing /dev/st0: Input/output error

summary:  0.0 KiByte in 14.9sec - average of  0.0 KiB/s
mbuffer: warning: error during output to /dev/st0: Input/output error

I've checked the man pages for MT and using 'eod' instead of asf, fsf and god knows what else!
Does anyone have any ideas on what I can try next please?

[TrevorH]

I think you write to /dev/nst0 not /dev/st0.

[badgerfruit]

I think you write to /dev/nst0 not /dev/st0.

Thanks ... do you mean initially, subsequently or all the time?

ps. What's the difference with nst0 vs st0 ?

[TrevorH]

/dev/st0 rewinds every time, /dev/nst0 does not.

[badgerfruit]

B I N G O!

Thank you, so, starting with a fresh tape, I am writing to the tape with:

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tar -c /tmp | mbuffer -t -m 2048M -P 80 -o /dev/nst0

Then I can repeat that command with different source folders successfully

To read, I initally do

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dd if=/dev/st0 bs=1M | tar -tvf -

... fast forward to the next tar with:

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mt -f /dev/nst0 asf 1

and then repeat the read command and I can see my 2nd write!!
Now to put this into a working script (although I feel this is a job for Monday!)


@TrevorH, thank you for your assistance and patience, it really is appreciated and my god, my head is sore from all the googleing, trials and errors!
Many thanks

Richard