I would expect growth close to 14 times your nightly run.  The reasoning is you 
already have a copy of the stuff that does not change and you already have a 
copy of the last 7 days.  You are adding 14 more days.  There will be some 
shrinkage from the objects that do not make the 7 changes in 90 days because 
the older of them will drop off sooner.

If the change is made I would be interested in the actual results.

Andy Huebner

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Dennis, Melburn (IT Solutions US)
Sent: Wednesday, March 18, 2009 7:47 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: [ADSM-L] Calculating Change in Backup Environment

Currently, our backup environment employs a 90-day / 7 revision backup
policy.  My customer has come to me to find out how much our backup data
would grow or shrink if we went to a 21-day / 21-revision backup policy.
Have any of you out there experience requests like this before, and if
so, how were you able to get a reasonable guestimate of this.
 
Mel Dennis
Systems Engineer II
 
Siemens IT Solutions and Services, Inc.
Energy Data Center Operations
4400 Alafaya Trail
MC Q1-108
Orlando, FL 32826
Tel.: 407-736-2360
Mob: 321-356-9366
Fax: 407-243-0260
mailto:melburn.dennis AT siemens DOT com
www.usa.siemens.com/it-solutions
 


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