A couple of RAIT questions (Running amanda 2.5.1p2 on
solaris10) :

1) The wiki says RAIT with tape changers is not     
supported. Is this true?   

2) Does tape spanning work with RAIT tape mirroring?

3) Anyone used the 'amdd' utility to do mirrored tape
backups  using native tools (gtar for example)?  I am
trying to do mirroring with two LTO3 drives.  I can
spin a single drive up to 60-70MB/s backups and
40-50MB/s restores, but I can only best out at 30MB/s
with a mirrored backup.  A restore from one of the
mirror tapes runs at only 9MB/s!  

  For example, the backup command I used:
/usr/amanda/gtar/bin/tar -b512 -cf - . | dd \
obs=512b | /usr/amanda/sbin/amdd -d bs=512b \
of='rait:{/dev/rmt/5hbn,/dev/rmt/4hbn}'
(I needed to double buffer in order to get the
35MB/s).

To restore:
/usr/amanda/gtar/bin/tar -b512 -xf /dev/rmt/4hbn
  
Not sure why I am getting only 9MB/s from the single
tape when we can do 50MB/s from a non-mirrored backup.

Just looking for any quick suggestions.  I don't think
it is a hardware limitation issue since I got similar
results on a more powerful system.

Thanks,
-JB



 
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