On Friday 07 January 2005 15:40, Brian Cuttler wrote:
>samar 5# /usr/local/sbin/amrestore -r /dev/sdlt2
>amrestore:   0: skipping start of tape: date 20050107 label SAMAR05
>amrestore:   1: restoring samar._usr5_amanda.20050107.1
>amrestore: read error: I/O error
>
>samar 6# mt -f /dev/sdlt2 rewind
>samar 7# mt -f /dev/sdlt2 fsf 1
>samar 8# dd if=/dev/sdlt2 bs=32768 of=samar._usr5_amanda.20050107.1
> skip=1 Read error: I/O error
>1+0 records in
>1+0 records out
>
>samar 9# mt -f /dev/sdlt2 rewind
>samar 10# mt -f /dev/sdlt2 fsf 1
>samar 11# dd if=/dev/sdlt2 bs=32768 of=samar._usr5_amanda.20050107.1
>Read error: I/O error
>1+0 records in
>1+0 records out
>
>samar 12# mt -f /dev/sdlt2 rewind
>samar 13# mt -f /dev/sdlt2 fsf 1
>samar 14# cat -evt /dev/sdlt2 | more
>Input error: Invalid argument (/dev/sdlt2)
>
>samar 15# mt -f /dev/sdlt2 rewind
>samar 16# mt -f /dev/sdlt2 fsf 1
>samar 17# dd if=/dev/sdlt2 bs=32768| cat -evt | more
>AMANDA: FILE 20050107 samar /usr5/amanda lev 1 comp .gz program
> /usr/local/sbin/ gnutar$
>To restore, position tape at start of file and run:$
>^Idd if=<tape> bs=32k skip=1 | /usr/sbin/gzip -dc |
> usr/local/sbin/gnutar -f... -$
>^L$
>^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@
>^@^@^@^@^@^@
> ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^
>@^@^@^@^@^@^@
>
>
> ** many null characters removed.
>
>
>
>samar 18# mt -f /dev/sdlt2 rewind
>samar 19# mt -f /dev/sdlt2 fsf 1
>samar 23# dd if=/dev/sdlt2 bs=32768 skip=1 | /usr/sbin/gzip -dc |
> /usr/local/sbin/gnutar -tf - | more Read error: I/O error
>0+0 records in
>0+0 records out
>
>gzip: stdin: unexpected end of file
>
>
>I had followed Gene's instructions and saved the label via DD and
>restored it to the tape as shown in an earlier email. This was the
>procedure to set the blksize in the tape and dd the label back.
>
>samar 24# mt -f /dev/sdlt2 blksize

This is querying the tape only, and I guess the bigger tapes like 
bigger blocksizes by default.
> Recommended tape I/O size: 131072 bytes (256 512-byte blocks)
> Minimum block size: 4 byte(s)
> Maximum block size: 16777212 bytes
> Current block size: Variable
This I think, is not good.

>I am using /dev/sdlt2 link to /dev/rmt/tps1d4nrns - no rewind,
> non-byte swap device. I am no longer using the trailing 'v' device
> which would normally provide variable length blocks.
>
>I will demonstrate with the next tape SAMAR06 in slot 5.
>
>samar 27# mt -f /dev/sdlt2 rewind
>samar 28# dd if=/dev/sdlt2 of=./scratch
>Read error: Invalid argument
>0+0 records in
>0+0 records out
>
>Remembering that I'd setblksize yesterday prior to running amlabel
> -f
>
>samar 29# dd if=/dev/sdlt2 of=./scratch bs=32k
>1+0 records in
>1+0 records out
>
>samar 30# ls -las scratch
>  64 -rw-r--r--    1 root     sys        32768 Jan  7 15:36 scratch

Ok, what happens if you don't spec the blocksize, but just a count of 
1 on a rewound tape.  Then what size of scratch file do you get?

>AMANDA: TAPESTART DATE X TAPE SAMAR06$
>^L$
>^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@
>^@^@^@^@^@^@
> ^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^
>@^@^@^@^@^@^@
>
> ** many nulls removed
>
>
>samar 32# mt -f /dev/sdlt2 blksize
>
> Recommended tape I/O size: 131072 bytes (256 512-byte blocks)
> Minimum block size: 4 byte(s)
> Maximum block size: 16777212 bytes
> Current block size: 32768 byte(s)
Aha, this one should be ok.

>samar 33# mt -f /dev/sdlt2 rewind
>
>samar 34# mt -f /dev/sdlt2 blksize
>
> Recommended tape I/O size: 131072 bytes (256 512-byte blocks)
> Minimum block size: 4 byte(s)
> Maximum block size: 16777212 bytes
> Current block size: 32768 byte(s)
>
>samar 35# dd bs=32768 if=scratch of=/dev/sdlt2
>1+0 records in
>1+0 records out
Which should have obtained the tapes label block, probably with about 
32700 bytes of nulls appended.
>
>That out of the way I'll go back and see what the other outstanding
>questions/tests where.

I hope I haven't confused things here, but it seems you might be 
getting closer Brian.

-- 
Cheers, Gene
"There are four boxes to be used in defense of liberty:
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Copyright 2004 by Maurice Eugene Heskett, all rights reserved.