I am considering changing my backup strategy from using backup tape to using a product from EMC called Avamar. I have a Corp Data Center and a Disaster recovery Data Center. The plan is to put Avamar units in both DC's and replicate between the two fulfilling our SLAs requirement for off site backups. I was just pitched the Avamar product and was impressed, now I want the cold hard facts about the solution. What are the pros and Cons of going this route and what is the good the bad and the ugly with the Avamar product?


If it's not capable of being taken offline and taken off-site, it's not backup. When the site is destroyed, the "backup" will be gone too.

Corollary: If it's off-site but always online, it's not backup. If you leave it online, the attackers can destroy it right after they destroy the production copies. Hacking across an air gap (read: physical security) is much harder than over a wire.


Food for thought - a very large financial company did the same thing. They had EMC SANs in both of the world trade center towers and lost everything.

So, how far apart are your two data centers?

For my company we have nearly 5,000 customers (web sites, web applications, hosted systems, etc...) We have a DR plan that uses both disk based replication to a geographically separate data center as well as tape backup.

Tape backup allows us to give certain customers longer retention as we off load from disk. We host some applications for large companies who are mandated by the US federal government to keep certain records on file for so many years and tape is the only real cost effective solution in these situations. Something to think about.

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    the DC's are about 3000 miles apart one is in the east the other in the west. – TechGuyTJ Jul 9 '09 at 18:19
  • At 3000 miles, I would imagine you have a latency of around 40 to 50ms; typical of a major telecom using DWDM. So your replication is either write local and wait for the remote to return or cache & queue. So naturally, you have to decide if this is good enough for DR. For backup, you still haven't spoke to the retention needs and to the importance of historical data. Importance is typically the cost to the company if the data was lost for good. – Kilo Jul 9 '09 at 21:33

I see one potential problem : if you use Avamar on both sites, and that some problem hits the Avamars (for instance some weird bug, or a license related problem) you may be out of order on both site at the same time or close. A true backup is both offsite and offline, and in an open and easy to read format (open standard encryption like PGP, open data format like TAR or CPIO, etc).

Only the paranoids survive :) See the still funny Tao of backup. Particularly notice the section "Keep some old backups".

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