[CLUE-Tech] Help w/SCSI tape problem?

[Carl Gibbons]

I didn't get any results the first, time, so I'd like to try one more 
time. Perhaps nobody reading this mailing list does any tape stuff with 
Linux?

I tried it again with a text file (/etc/termcap), and it's the *end* of 
the file that I'm missing when I try to read it back from the tape:

$ sudo dd bs=512 if=/etc/termcap of=/dev/nst0
dd: writing `/dev/nst0': Invalid argument
1440+1 records in
1440+0 records out
$ sudo mt -f /dev/nst0 rewind
$ sudo dd bs=512 if=/dev/nst0 of=image
3397+0 records in
3397+0 records out
$ diff /etc/termcap image
Warning: missing newline at end of file termcap
17095,17104c17095
< # The following sets edit modes for GNU EMACS.
< # Local Variables:
< # fill-prefix:"\t"
< # fill-column:75
< # comment-column:0
< # comment-start-skip:"^#+"
< # comment-start:"# "
< # compile-command:"tic -c terminfo.master"
< # End:
< ######## SHANTIH!  SHANTIH!  SHANTIH!
---
> # 

Insights appreciated!  -Carl

Carl Gibbons wrote:

>   I can see the tape drive and tape:
>
>$ sudo mt -f /dev/nst0 status
>SCSI 2 tape drive:
>File number=0, block number=0, partition=0.
>Tape block size 512 bytes. Density code 0x8c (EXB-8505 compressed).
>Soft error count since last status=0
>General status bits on (41010000):
> BOT ONLINE IM_REP_EN
>
>   I can write to the tape, but I get an error:
>
>$ sudo dd bs=512 if=liquidwar-5.5.9-1.i386.rpm of=/dev/nst0
>dd: writing `/dev/nst0': Invalid argument
>3397+1 records in
>3397+0 records out
>
>   I can try to read what I wrote to the tape:
>
>$ sudo mt -f /dev/nst0 rewind
>$ sudo dd bs=512 if=/dev/nst0 of=image
>3397+0 records in
>3397+0 records out
>
>   But what I read back isn't the same size as what I wrote:
>
>$ ls -l
>-rw-r--r--    1 root     root      1739264 Apr 25 15:55 image
>-rw-------    1 johndoe  johndoe   1739593 Apr 24 15:08 liquidwar-5.5.9-1.i386.rpm
>
>   Why is this happening? How do I fix this problem?
>
>-- Carl Gibbons, cgibbons at du.edu
>  
>