What I have seen in the past is the compression value is dependent on what
you back up. For instance a volume that is not full yet will usually show an
estimated capacity of 70 gb. But it is basing that number on whatever was
placed in estimated capacity in the device class.

 But if you backup without compression or a lot of image files where
compression may not take place at all the amount of data on the tape is only
going to get to 35 - 40 gb. I have the same tapes and my db backups fill a
tape at 35 GB , but a File & Print system will fill a tape to 90 - 100 gb
because of higher compression.

Duane

-----Original Message-----
From: Eddie Jones [mailto:Eddie_Jones AT CANADALIFEUS DOT COM]
Sent: Thursday, May 08, 2003 2:47 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: amount of data on a tape


Hey gang.

We are running 35/70 dlt drives on a windows nt 4.0 tsm server.  Some of
the tapes it will have full with 30gb of data and other tapes will have
60-90gb of data.  Is there a setting in tsm that can help with this or
should I be looking at my tape drive?  What would cause me not to get
60-70gb of data per tape.  Any information would be appreciated.


Eddie Jones
770-953-1959 ext.2824

"The greatest lesson in life is to know that even fools are right
sometimes."
- Sir Winston Spencer Churchill


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