While at PASS this year I heard that it was a bad idea to have your backups on deduplicated storage. The reason was that if a single block was lost or corrupted beyond repair, you could loose multiple generations of backups if they all shared it in common. I've tried to search for more information, but I haven't found anything that directly addresses this. When I asked the SAN guy he said not to worry as it did some sort of parity calculation to allow for recovery in case of corruption, and this wasn't a concern. At any rate the SANs are geographically mirrored so that there is at least one other copy. Still, I can easily see a nightmare scenario with a corruption and crash magnified by us being in an auto-tiering configuration.
Anybody have any advice or know of any resources that discuss this? Thanks!