RE: [Bug-tar] Problems restoring from multi-volume DLT tape archi ve

[Petcher, Daniel]

Hmmm... Tar was working well for me with multiple tapes, once I upgraded to
1.19, but I did a little more hand-holding: I prepared a list of elements I
wanted archived in a separate file, I searched-out the device number of my
tape drive (depending on which hard drives I had mounted at boot, the device
number could change on me), I captured logs of the tape activity to files,
and I made a script to get my auto-loader to advance to the next tape with
the mtx command. Here's the tar statement from my script:

 tar --create --one-file-system --atime-preserve --totals --sparse -vv \
      --multi-volume --new-volume-script "nexttape sg$drv" \
      2>> /tmp/tarc.err 1>> /tmp/tarc.out \
      --file /dev/nst0 -T /tmp/tapeindex.txt --label=$1

Afterward, I reloaded the first tape and did a compare operation to verify.
Here's THAT tar statement:

if tar --compare --directory / --file /dev/nst0 --sparse -vv \
       --multi-volume --new-volume-script "nexttape sg$drv" \
       2>>/tmp/tard.err 1>>/tmp/tard.out ; then
        echo "Verified OK"
else
        echo "Errors in verify" $status
fi


Here's my "nexttape" script:
#!/bin/sh
PATH=/bin:/usr/bin:/usr/local/bin:/usr/sbin

# Flush status file
: > /tmp/nexttape.txt

mt -f /dev/nst0 rewind >> /tmp/nexttape.txt 2>>/tmp/nexttape.txt
mtx -f /dev/$1 next >> /tmp/nexttape.txt 2>>/tmp/nexttape.txt

if grep "Loading media from Storage Element" /tmp/nexttape.txt ; then
        echo "successful tape advance"
        echo "successful tape advance" | mail -s "Tape advance success"
address@hidden
        let sorce=`grep "Unload" /tmp/nexttape.txt | sed -e 's/\./ /' | awk
'{print $7}'`
        let trgt=`grep "Loading" /tmp/nexttape.txt | awk  '{print $6}'`
        echo "From " $sorce
        echo "To " $trgt
else
        echo "tape advance fails"
        let sorce=`grep "Unload" /tmp/nexttape.txt | sed -e 's/\./ /' | awk
'{print $7}'`
        cat /tmp/nexttape.txt | mail -s "Tape $sorce advance fails"
address@hidden
        echo "Unloaded from " $sorce
fi

Ultimately, I've had to abandon tar because I needed stronger database
management of what data are on which tape in order to satisfy my boss'
Recovery Time Objectives. I'm in the middle of testing Storix, Arkeia, and
NovaNet, three commercial programs that will also allow me to backup across
the network.

-dP

-----Original Message-----
From: address@hidden
[mailto:address@hidden On Behalf Of
Leonard Sitongia
Sent: Tuesday, February 19, 2008 11:26 AM
To: Petcher, Daniel
Cc: address@hidden
Subject: Re: [Bug-tar] Problems restoring from multi-volume DLT tape archi
ve

Leonard Sitongia wrote:
> It's going to be an hour more before it gets to the end of the tape, 
> so that I can see if upgrading tar fixes the problem of the lost file 
> between the two tapes.  But, I wonder if it is going to end like 
> before, just finishing at the end of the first tape, without prompting 
> for the 2nd tape, because it thinks it is already on the 2nd tape.
The new tar on Linux made the situation worse.  As before, when it finishes
reading the first tape, it doesn't prompt for the second tape, it just ends.
So, I load the second tape, and run tar, and it says:

# ~sitongia/bin/tar -xv -M -b 128 -f /dev/nst0 20050421/20050421.121910.fts
/home/sitongia/bin/tar: 20050421/20050421.121910.fts: Cannot extract -- file
is continued from another volume
/home/sitongia/bin/tar: Skipping to next header
/home/sitongia/bin/tar: Error exit delayed from previous errors

Previously, it would give the error about the continued file, and then
continue reading the tape.  With tar 1.19, I cannot read the second tape.

--
==Leonard E. Sitongia
   High Altitude Observatory
   National Center for Atmospheric Research
   P.O. Box 3000 Boulder CO 80307  USA
   address@hidden  voice: (303)497-2454  fax: (303)497-1589