Rosa,

Ah yes...tape capacities.

We have a mix of "B", "C", and "XL" tapes in libraries with "B" and "XL" drives.
This is what I've seen.

(Embedded image moved to file: pic07200.pcx)

Our 3570 and 3575-L06 libraries have B drives in them.  "Old" B tapes have
lables beginning with less than "25xxxx", "new" B tapes a labeled "25xxxx" and
higher.

Our 3575-L12 has XL drives in it and XL tapes exclusively.

Our 3575-L18 has XL drives and a mix of old Bs, new Bs, Cs, and XLs.

As you can see, the capacities are all over the map.

These statistics are calculated over a total tape count of 312 tapes.

I've opened a PMR and discussed this at length with IBM.  Their answer is the
"long version" of "your mileage may vary."

Tab







"Rosa Leung ( rosal/@ibmca tel : (416)-490-5151)" <rosal on 07/12/2000 08:22:25
AM

Please respond to "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>

To:   ADSM-L AT VM.MARIST DOT EDU
cc:    (bcc: Tab Trepagnier/Corporation/Laitram/US)
Subject:  Re: compression on XL 3570 tapes




I have client,
1. install TSM 3.7.0 onto AIX box as backup server
2.using 3575 L24 library with XL (red) 3570 tapes,
3. backup Notes 5 database (on NT servers),
4. TDP  agent is installed,
5. Client and server compression are turnd off, let the hardware do the
compression

The backup is setup smoothly, but the capacity on tapes are not very good.
AIX clients, NT clients, and TDP domino clients all at 9 GB per tape, which
we expect at least 15 GB towards 21 GB.



Anybody,has the same environment like the above, can get better rate?  If
you have green or blue tab of tape, what kind the capacity rates they have?


Rosa Leung
Distributed Storage Services
Tel: (416) 490-5151  Fax: (416) 490-5283
rosal AT ca.ibm DOT com   BK02/245/TOR
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