Avamar and Riverbed WAN Accelerator

I'm not aware of any adverse effects. There will be no benefit to the de-duplication features (the data has already been de-duplicated) but WAN accelerators often "abstract away" packet loss on the WAN which can give Avamar replication a big boost on less reliable networks because the dropped packet doesn't cause a TCP reset which means we don't have to start over at the smallest window size and "ramp up" again to hit peak performance.

Having had extensive experience with Riverbed for "Over WAN LAN" traffic and broad experience with Avamar, I can tell you  that it does have a slight negative impact on the Riverbed performance for the deduping of normal network traffic.

Many times in the past, I’ve offered a slightly technical explanation as to why this does not offer any benefit, and actually does cause a little negative performance issues.

After the discussion I make the following comparison Summary.

Since Avamar Dedups between the Client and the server, it only transmits network packets that are unique, and therefore only transmitted once. If you put in a Riverbed/Steelhead solution between the Avamar Server  and the clients, since every network package is unique the Riverbed appliance will record it in its local cache and transmit the full packet. Since that packet is never transmitted again the data just takes up cache space on the Riverbed that could be used for real repeating network transmissions.

It is kind of like Zipping up a Zip file, you don’t get any more compression out of it, but the result is a slightly larger zip file, and you used extra resources to do the second zip and unzip to do it, resulting in negative benefits.

But if you can configure the Riverbed to ignore certain specific IP port packet traffic, that is used by Avamar client server communications, you can still use Riverbed to speed up your normal over WAN traffic without negatively impacting the performance of the Avamar Backup traffic, or the regular network traffic over the Riverbed solution. There is your Win-Win. The same is true with DD and Riverbed.

Summary: Dedup over Dedup offers no benefits, and even adds a little negative Benefit.