Michael, 

Look at the b option to increase your blocking size. Use man tar on your host 
to check for the fine print. If your tar program will let you do it, aim for 
256K block sizes. 

len

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Michael Green
Sent: Monday, July 09, 2007 10:47 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: [ADSM-L] tar with LTO2

This post is a bit offtopic, but still I decided to send ti here
because it's probably one of the very few places where large amount
backup administrators that are invested in IBM equipment come
together.

My question is related to using old school tar with IBM LTO2 drives.

I was asked to archive a rather large directory (over 200GB) to tape
using tar and put it into vault for indefinite period of time.
My equipment is as following: Linux x64 (IBMtape driver), 3584 Libr
with IBM 3580 LTO2 FC-attached drives.

I've tried to load a tape into IBMtape0 drive using 3584 Library
Specialist WebGUI and IBMtapeutil
then I tried to write a small directory '/var/log' to the tape as following
tar cvpf /dev/IBMtape0  /var/log
and it seemed to work. I could also tar xvfp  /dev/IBMtape0 and read
the resulting files.

However, tar'ing the actual target directory revealed that the data is
flowing at extremely low rates - less than 100kb/sec.

Any ideas?
--
Warm regards,
Michael Green