Depends on your data.   File systems usually have a large volume of
already compressed files, or files that don't compress much (jpgs, mpg,
mp3, etc).  In our windows environments, we get about 300-400 on LTO-2
and 700-900 GB on LTO-3 tapes.   

Less capacity on Exchange tapes 500-600 on LTO-3 tapes. 

SQL (in our environment) gives the best compression results, and we can
get over 2,000 TB on a LTO-3 tape. 

Your results may vary. 

David M. Browning Jr.
IT Project Coordinator Enterprise Backups and Help Desk

 

-----Original Message-----
From: EMC NetWorker discussion [mailto:NETWORKER AT LISTSERV.TEMPLE DOT EDU] On
Behalf Of Eugene Vilensky
Sent: Thursday, March 27, 2008 2:06 PM
To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Subject: [Networker] tape utilization

Hello,

Forgive me if this is obvious and has been asked before, but is %used
the correct attribute to look at for "tape utilization" ?  I am new to
Networker, (7.2.2), and I am wondering if a "full" LTO-3 volume really
has 400GB/800GB compressed on it.  I attended a presentation from
Curtis Preston that said high 90% is an excellent utilization rate,
with some real-world hovering around 40-60% (I think) so I doubt all
of our volumes are being utilized 100%.

Thanks,
Eugene Vilensky

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