Re: Sizing on 3590 Tape

     ADSM will report the amount of "disk file space" written to the tape.
     So if a client sends a basically empty data base that occupies 200GB
     on their box and don't use compression it will occupy 200 GB in your
     diskpool, when it migrates to tape you might see...
     AAA078  3590P1       3590DEVC     200,000.0  100.0    Full
     if the client runs with client compression that 200 GB empty db file
     sent over might only occupy 9.8 GB in your diskpool and once sent to
     tape, since it is already compressed might look like...
     AAA078  3590P1       3590DEVC       9,800.0  100.0    Full

     The best I've ever seen is when I had 260 GB of user data on a single
     3590 tape ;-)  This is why, if you perform any sort of billing, you
     want to charge users based on the amount of data adsm says it has
     stored on tape rather than the physical number of tapes they are
     using.

     later,
           Dwight






______________________________ Reply Separator _________________________________
Subject: Sizing on 3590 Tape
Author:  tangeric (tangeric AT hk1.ibm DOT com) at unix,mime
Date:    9/10/98 2:44 AM


Dear All,

Offical 3590 tapes capacity  is 10GB (& upto 30GB with compression).

I use 3590 H/W compression & ADSM AIX v2 server (v2 client with no
compression & v3 client with compression) , from adsm "q vol", there
reports different estimated capacity for different type of backup data
(attached below). If estimation from ADSM is accurate, it seems that with
s/w compression, tape capacity is 9-10GB of the compressed data. If no s/w
compression, it can vary from 10GB to 63GB (even 100GB I haven't attached
here) depending on data type.

I am planning for implementing Oracle database backup, instance size range
from 100GB to 1.2TB. Those in Oralce7 will use SQL-Backtrack and those in
Oracle8 will use RMAN+ADSM ConnectAgent. Because of network capacity, will
use SQL-BT compression & ADSM compression for each case.

Just want to share your expreience on 3590 tape capacity so that I can plan
for the amount of tapes to be purchased with consideration of sets of full
backup image, retention period, amount of archived redo log ... etc.

Attachment:
Estimated capacity from "q volume " & the corresponding backup data (all
the volumes here are with "Volume status FULL" from q vol)

Estimated
Capacity       compression    Platform        backup data

9.052.6MB adsm client    Digital Unix    Oracle database in filesystem
9.082.1MB adsm client    Digital Unix    Oracle database in filesystem

9,346.7MB adsm client    HP        filesystem
9,387.7MB adsm client    HP        filesystem

62,695.9MB     no        HP        Oracle database in filesystem
63,873.0MB     no        HP        Oracle database in filesystem

10,509.0MB     no        HP        filesystem
12,109.4MB     no        HP        filesystem
32,123.5MB     no        HP        filesystem

9,812.2MB sqlbt          HP        Oracle database by SQL-BT


Regards,
Eric Tang / Hong Kong / IBM  @ IBMHK
Technical Services, Strategic Outsourcing,
IBM Greater China Group
Tel: (852)-2105-2119,   Fax: (852)-2861-2493
Notes: Eric KF Tang/Hong Kong/IBM@IBMHK
Internet : tangeric@ hk1.ibm.com