True as well as any files that are already "Compressed" We have SQL DB's doing Flat File Dumps to Disk with compression and we see 1.7:1 Ick..... Also TDP RMAN backups can use Files per set function which if set to more than 1 RMAN will "multiplex" each file set differently so you see different data every time. We have our RMAN set to files per set =1 then the DBA's run multiple channels so we see 20:1 of course our DBA's do fulls daily ....
We've even forced Compress = No in a Server Side Client option set, which only applies to File System backups, the compression statement does not apply to the TDP's as far as I know. Also do what you can to have Like Data go to the same dedupe devices (assuming you have more than one). Example Oracle Prod / Non-Prod with their associated OS's go to the Same Dedupe stgpoool, Exchange etc... Data DeDupe can be cool, but if you do not pay attention your data types you can ruin a good thing. I Cant wait to see how the newer Dedupe engines that are coming out that perform the DeDupe process "Out Of Band" compares to the Inband DeDupe methodology. Of course the Inbound Devices dedupes as data comes in which can affect Backup Performance, (just add more widgets) but it will be interesting to see how "Out of Band" dedupe methodology will perform if you "get behind" (i.e. Days one Backup Data is still being DeDuped while your are taking in Day 2's Backup data, then you add in Backup Stgpool, Reclamation etc that will force the dedupe engine to re-dupe / re-factor the data everytime the data is read..... There's been many Dedupe Threads in this user list, you could almost write a VTL - DeDupe Best Practice Guide. -----Original Message----- From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of Wanda Prather Sent: Wednesday, January 23, 2008 9:42 AM To: [email protected] Subject: Re: [ADSM-L] Data Deduplication Oooh, what a great question! I'd guess if client encryption is on and working, the dedup ratio should be about 1:1; because the data should never encrypt the same way twice. On 1/23/08, lamont <[EMAIL PROTECTED]> wrote: > > Hi, > What would likely be the de-dupe ratio if tsm clients do archive > processing daily (file level, no tdps) with encryption enabled? > > Thanks. > > +--------------------------------------------------------------------- > +- > |This was sent by [EMAIL PROTECTED] via Backup Central. > |Forward SPAM to [EMAIL PROTECTED] > +--------------------------------------------------------------------- > +- > This e-mail, including attachments, may include confidential and/or proprietary information, and may be used only by the person or entity to which it is addressed. If the reader of this e-mail is not the intended recipient or his or her authorized agent, the reader is hereby notified that any dissemination, distribution or copying of this e-mail is prohibited. If you have received this e-mail in error, please notify the sender by replying to this message and delete this e-mail immediately.
