Upgraded from 2010 R3 to 21012 this past week.
I have gotten almost 5GB/Min of backup speed off my cluster file share for the past year when doing a full backup on the weekends.
Now that I moved to 2012 that speed dropped to 2GB/Min this weekend for the 1st full backup using the new version.
Agents are installed on all cluster host nodes as it was with 2010 R3. Cluster hosts were rebooted after the remote agent was upgraded.
I was able to get almost 4GB/Min from another file server during the full backups this weekend so it is not a library or connection issue.
All servers reamined the same. Only the BE version changed.
The media server is and was a Proliant ML350 using an Overland Neo 200 library with a LTO5 tape drive.
My Cluster is a MS Cluster using 2 Proliant ML350 and a ML370. The SAN is a 4 node HP P4500 (Lefthand). Everything is fully patched, 2008R2 SP1, newest firmware for the SAN and MPIO drivers.
I have not removed the RAWS and reinstalled. That is labor intensive and this entire upgrade process comsumed way more time than I would have expected. I will do that next.
Also I tried the backup using both the Shares path and the direct path to the folder in the drive, ex: z:\data\projects. Same speeds.