R3 Deduplication Performance

[jakins]

In my reading,  I have gotten the impression that I should be seeing increased backup speeds and shorter windows after a period of time with BE deduplication.  We have been using client side dedup on all of our jobs, with a weekly full and daily differentials.

There has been no change over the last three months in the amount of time it takes to process either the full or differential backups.

When reviewing jobs I am seeing that we are only sending 1% or so of the files that are processed on the client end.  Are there any tuning parameters within client side dedup that help the remote agent process the files faster?

[Speeder]

It's a common misconception. Even though no data is being sent across, it still takes a long time to go through the entire filesystem, and hash the files to compare the data to what's in the Dedup DB. More files = slower backup, even if the data is 100% stale.
The only time you'll see a benefit in the current model is if the backup is happening over a slow link (WAN) and the bottleneck is the WAN bandwidth. In a "Datacenter", since LAN speed is hardly ever a bottleneck, there will be no noticable performance improvement.

There will be no increase in backup speed until Symantec switches to PureDisk style client change tracking with Forever Incremental model -
A) Initally do a complete full (takes a long time)
B) Track Changes between backups (via Windows Change Journal (?)) / Keep a cache of all hashes
C) Backup Only Changed Files
D) make a "synthetic" point in time list of all restoreable data to simulate a full

The above process makes backups 10-100x quicker. As far as I know, the change is going into Netbackup with release 7.5, and I have no idea if and when BackupExec will get that functionality.

Symantec PureDisk, and EMC Avamar have that functionality already

Symantec's (upcoming) press release on the topic: http://www.betterbackupforall.com/?locale=en_us

[jakins]

This whole solution is junk as far as I am concerned.  I have a pile of issues with Dedup and performance is just the tip.

This process would shorten my window, if I could get around the 75% hit that the DEdup process is hitting me with.  I can windows file copy to the media server at 4 times the rate that Dedup is operating. 

Should I be seeing a hit on performance like that?