As many say your mileage may vary.... You can positively impact the Dedupe 
factor by ...

1) No Client Side Compressions (Compressed files always have unique Sig)

2) No Client Side Encryption (TSM or OS) - Encrypted Data is always unique like 
compressed data.

3) If you have more than one VTL each with its own repository - do your best to 
keep like data together (i.e. all Unix / Oracle data to one VTL, all Windows 
based Data on 2nd VTL etc .... If would have 200+ Windows OS's you'll see some 
Deduping... 

4) Of course the Dedup for full DB backups gets much higher (21 Versions of 
Fulls we avg 15:1)  Our challenge has become I/O not space.

5) According to our VTL vendor the RMAN Files per set option should be @ 
1(Files perset allows Oracle to mix data backup streams there by creating 
unique data...

Good luck on your venture looks like the TS7569G (IBM Protectier?) same we are 
using... The most challenging aspect of any VTL is capacity planning assuming 
you have solid retention policies that are followed ... 


Regards 

Charles 

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Christian Svensson
Sent: Thursday, March 19, 2009 7:42 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: [ADSM-L] SV: VTL and Dedup ( TS7569G)

Hi Martin,
The 1st Backup will probably don't do any major save for you. It always depend 
on what kind of data you backup.
What we normally see is saving on Archive Data and TDP Data. Everything else is 
most of the time unique data and you will not see any saving.

Dedup is a major saving for other backup software such Legato and NBU not for 
TSM because you are using Incremental forever.

Best Regards
Christian Svensson

Cell: +46-70-325 1577
E-mail: Christian.Svensson AT cristie DOT se
Skype: cristie.christian.svensson
________________________________________
Från: ADSM: Dist Stor Manager [ADSM-L AT VM.MARIST DOT EDU] för Sabar 
Martin Hasiholan Panggabean [Sabar.Hasiholan AT METRODATA.CO DOT ID]
Skickat: den 19 mars 2009 13:09
Till: ADSM-L AT VM.MARIST DOT EDU
Ämne: VTL and Dedup ( TS7569G)

Hi,


Does anyone here has been implementing or know how Dedup works in TSM using 
TS7569G ? Let say I have 100 TB of data and backup to this VTL. On the 1st 
attempt of backup / full backup, will this data size decrease on the VTL

BR,

Martin P

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