We have a number of Data Domains and we generally see a 12:1 reduction in size with TSM.
IMO the ratio can be deceiving and confusing, we have found that many of our sites using a variety of backup products see their backups (all of the versions, fulls, etc.) reduced to about 1/4 of the size of the protected data. Or put another way, if they are protecting 100TB of data with a 90 day retention, that turns into about 25TB on the Data Domain after the DD has been in place 90 days. TSM might have a ratio of 12:1, BackupExec might be 30:1, but the 1/4 rule works the same for both. With all of that said, our data does not contain large amounts on non-compressible files, video, pictures and such go to tape. We recommend DD purchases to our sites that are 1/2 the size of the data to be protected. This leaves room for growth and gives us time to locate non-compressible data if needed. Hope this helps. Andy Huebner -----Original Message----- From: ADSM: Dist Stor Manager [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Weidacher, Daniel Sent: Thursday, January 02, 2014 2:01 AM To: ADSM-L@VM.MARIST.EDU Subject: [ADSM-L] Copy Pool - Tape Library or VTL? Hello, In our company we have a TSM 6.2 Server with a TS3310+Extension (LTO-4) Library for primary pools and an Overland Library for copy pools (LTO-2). Now the Overland is nearing retirement and we need a replacement. We have 46 Nodes with a total of ~16TB in need of a copy pool (with more nodes in tsm, but they are not that important). Of that 16TB, 3-4 TB are MSSQL and Oracle Databases, the rest is Windows and Linux Operating Systems. The way I see it, there are two options. 1: We get another TS3310 base model with LTO-5 drives (or any other Tape Library). We would get about 38TB in 24 Tapes, and we probably have to turn off collococation. If necessary we could get an Expansion for the Library. 2: We get a Virtual Tape Library, say a TS7620 with 24TB Diskspace (12x2TB Disks), which would cost as much as the TS3310 (more or less). I could make a lot of small volumes (say 50-100GB) which would probably increase restore speed in comparison to a real Tape Library. On the other side, the VTL has less raw space. But with data-deduplication we probably could get much more out of it. And that's my problem: I did some numbers after reading some guides on the web, and results vary from data-reduction of 10-50%, but we really have absolutely no experience with data-deduplication. Can anybody please give me some advice on what would be the best option? What are your experiances with VTL and data-deduplication? Would even a smaller VTL be sufficient? Any help would be really appreciated. Kind Regards, Daniel ________________________________ INFONOVA GmbH Sitz: Unterpremst?tten bei Graz Firmenbuchgericht: Landesgericht f?r ZRS Graz Firmenbuchnummer: FN 44354b The information in this email is confidential and may be legally privileged. If you are not the intended recipient of this message, any review, disclosure, copying, distribution, retention, or any action taken or omitted to be taken in reliance on it is prohibited and may be unlawful. If you are not the intended recipient, please reply to or forward a copy of this message to the sender and delete the message, any attachments, and any copies thereof from your system.
