[KLUG Members] backing up

[Adam Williams]

>I am having a little trouble backing up.  I am using tar as follows:
>tar -cvzpf /dev/st0 -T /root/backup/whattobackup
>when I restore the files with :
>tar -xvzpf /dev/st0 it restores and then hangs.  When I try backup and then
>restore a small amount of data it completely hangs and fails on the restore. 
>(control c stops the hang.)
>The tape device is a 4mm dat.  Here is from dmesg
>Vendor: SEAGATE   Model: DAT    06240-XXX  Rev: 8160
>Type:   Sequential-Access                  ANSI SCSI revision: 03
>Anyone have any ideas for why it is hanging at the end of long restores and not
>restoring small backups at all?

No, but I had the EXACT same thing with the EXACT same tape drive. 
Fought with it forever.  A little TLC and the tape drive started eating
the tapes and the OEM swapped it out as a bad unit.  Works great now.

>On a side note, for network backups of files on a host without the tape drive,
>what is your preferred method.  I have been using tar and ssh with some luck as
>follows:
>tar -czp TEST* | ssh srv2 'cat > /BAI.unidata/BAI.accounts/TEST.tgz'
>but this is done to a file and not to a tape device.  Is it perfectly acceptable
>to do this
>tar -czp TEST* | ssh srv2 'cat > /dev/st0'

No.  You should write to the tape drive with dd so you can set the block
size.

>I also noticed from man tar that you can put a hostname before a tar.   -f,
>--file [HOSTNAME:]F  What mechanism does this use and does it work/is it secure
>like with ssh.

rmt via rexec.  It is secure only on a Kerberos network,  on "standard"
networks it is hilariously not secure.