IBM supplies a perl script to measure the cost of dedup.
See http://www-01.ibm.com/support/docview.wss?uid=swg21596944
I just ran it in an instance with an 800 GB db, here are the final summary
lines -
----------------------------------------
Final Dedup and Database Impact Report
----------------------------------------
Deduplication Database Totals
-----------------------------
Total Dedup Chunks in DB : 1171344436
Average Dedup Chunk Size : 447243.5
Deduplication Impact to Database and Storage Pools
---------------------------------------------------
Estimated DB Cost of Deduplication: 796.51 GB
Total Storage Pool Savings: 230466.30 GB
That works out to ~3.5 GB per TB saved.
The db is not on SSD. It is on a 6 disk raid 10 array internal on a Dell
server.
Overall I am very happy with TSM dedup.
Thanks,
Bill Colwell
Draper lab
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Dan
Haufer
Sent: Thursday, June 12, 2014 4:31 PM
To: ADSM-L@VM.MARIST.EDU
Subject: Re: TSM and VTL Deduplication
Yes, one of the two. If TSM deduplication is enabled and the target is a
virtual tape, i doubt if the VTL can deduplicate anything from the write data.
--------------------------------------------
On Thu, 6/12/14, Ehresman,David E. <deehr...@louisville.edu> wrote:
Subject: Re: [ADSM-L] TSM and VTL Deduplication
To: ADSM-L@VM.MARIST.EDU
Date: Thursday, June 12, 2014, 12:51 PM
Unless you have a
specific requirement, I would suggest you choose either TSM
dedup to disk or go straight to virtual tape. There is not
usually a need to do both.
David
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU]
On Behalf Of Dan Haufer
Sent: Thursday, June
12, 2014 2:41 PM
To: ADSM-L@VM.MARIST.EDU
Subject: Re: [ADSM-L] TSM and VTL
Deduplication
Thanks for
all the answers. So SSDs (Looking at SSD caching) for the
database storage and 10GB per TB of total backup data on
the safer side.
--------------------------------------------
On Thu, 6/12/14, Erwann Simon <erwann.si...@free.fr>
wrote:
Subject: Re:
[ADSM-L] TSM and VTL Deduplication
To: ADSM-L@VM.MARIST.EDU
Date: Thursday, June 12, 2014, 8:47 AM
Hi,
I'd rather say 6 to 10 times, or 10 GB
of
DB for each 1 TB of data (native, not
deduped) stored.
--
Best
regards / Cordialement /
مع تحياتي
Erwann SIMON
-----
Mail
original -----
De: "Norman
Gee" <norman....@lc.ca.gov>
À: ADSM-L@VM.MARIST.EDU
Envoyé: Jeudi 12 Juin 2014 16:55:29
Objet: Re: [ADSM-L] TSM and VTL
Deduplication
Be prepare
for your database
size to double or triple if you are using
TSM deduplication.
-----Original Message-----
From: ADSM: Dist
Stor Manager [mailto:ADSM-L@VM.MARIST.EDU]
On Behalf Of Prather, Wanda
Sent: Thursday,
June 12, 2014 7:15 AM
To: ADSM-L@VM.MARIST.EDU
Subject: Re: TSM and VTL Deduplication
And if you are on the
licensing-by-TB model, when it gets un-deduped
(reduped,
rehydrated, whatever), your costs
go up!
-----Original
Message-----
From: ADSM: Dist Stor Manager
[mailto:ADSM-L@VM.MARIST.EDU]
On Behalf Of Dan Haufer
Sent:
Thursday, June
12, 2014 9:48 AM
To: ADSM-L@VM.MARIST.EDU
Subject: Re: [ADSM-L] TSM and VTL
Deduplication
Understood.
Thanks !
--------------------------------------------
On Thu, 6/12/14, Ehresman,David E. <deehr...@louisville.edu>
wrote:
Subject: Re:
[ADSM-L] TSM and VTL
Deduplication
To: ADSM-L@VM.MARIST.EDU
Date: Thursday, June 12, 2014, 5:33 AM
If TSM moves data from
a
(disk) dedup pool to tape, TSM has to
un-dedup
the data as it reads it
