CentOS

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

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.

tunk wrote: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

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?

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

TrevorH wrote: ↑
2018/12/06 17:01:47
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 ?

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

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

CentOS

Using Ultrium 7 WORM tapes

Re: Using Ultrium 7 WORM tapes

Re: Using Ultrium 7 WORM tapes

Re: Using Ultrium 7 WORM tapes

Re: Using Ultrium 7 WORM tapes

Re: Using Ultrium 7 WORM tapes

Re: Using Ultrium 7 WORM tapes

Re: Using Ultrium 7 WORM tapes

Re: Using Ultrium 7 WORM tapes