David,

for what it is worth,

Here is a excerpt from a 'q vol' of some tapes marked as full from my
system.
----------------------------------------------------------------------------
-----

Volume Name               Storage      Device      Estimated    Pct   Volume
                          Pool Name    Class Name   Capacity   Util   Status
                                                        (MB)
------------------------  -----------  ----------  ---------  -----
--------
C00083                    TAPEPOOL     TAPE3590    203,025.7  100.0    Full
C00084                    TAPEPOOL     TAPE3590    152,142.7   42.2    Full
C00086                    OFFSITE      TAPE3590    195,116.3   95.4    Full
C00087                    TAPEPOOL     TAPE3590    206,932.1   65.6    Full
C00093                    TAPEPOOL     TAPE3590    196,629.9   34.1    Full
----------------------------------------------------------------------------
-----

Most of the backups are of Oracle DB on an AIX platform.  If I take into
account the size of the data being backed up and the est. cap. of the tapes,
once full, I would have to say that the est. cap. is fairly accurate.

Jim Taylor

-----Original Message-----
From: David DeCuir [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, June 20, 2001 10:58 AM
To: [EMAIL PROTECTED]
Subject: Data on my tapes


Hello,

Ok, how much data are you getting on a 3590 "K" tape. From reading past
posts, I know the Pct Util and Est. Capacity method is suspect at best. All
I need is an average you guys have seen using the following:
assume the tape is full and has had no files expired or reclaimed
3590 E1A drive
devclass FORMAT is set to DRIVE (should I be using something else?)
no client compression
drive compression
3590 extended K tapes

additional info if it helps:
data per tape is either all NT or all UNIX
mostly small files on NT
about half small files on UNIX and half Oracle database files (2-20gb)

The reason I ask is that my best guess seems to be such a wide range - I
think between 60 and 150 gb per tape.
Also, according to est. cap. and pct util, UNIX volumes shows about twice
the capacity of NT volumes

I know IBM says these are 40gb native and 120gb at 3:1 compression but what
is your real world experience of just how much data fits on a tape?

Thanks for your input
David
(still new, but learning everyday)

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