Heey David,

Dedup ratio's depend very much on type of data and how many copies of
DB backups you save.

Like if you have a very big database filled with plain text only and
save 30 uncompressed full backup versions of it, the dedup ratio shall
be around 30:1
But for a media server filled with unique allready compressed files
and backed up with progresive incrementals, the ratio shall be around
1:1

New data is mostly harder to compress and dedup, as the data is often
compressed allready. Like the new docx files, pdf's, mpg's, avi's,
jpg's.
So also the mailboxes are harder and harder to compress and dedup, as
most data is in the attachments.

Regards,
Maurice van 't Loo
TSM Freelancer


2010/11/12 Druckenmiller, David <drucked AT mail.amc DOT edu>:
> I'm curious what others are seeing for de-dup ratios for various methods.
>
> We're using IBM's ProtecTier for our TSM (5.5) primary pools and only see 
> about a 4 to 1 ratio.  This is less than half of what IBM was projecting for 
> us.  We have roughly 400 clients (mostly Windows servers) totalling about 
> 135TB of data.  Biggest individual uses are Exchange and SQL Dumps.
>
> Just wondering what others might be getting for other appliances or with TSM 
> v6?
>
> Thanks
> Dave