OK, here's my thought process: I have four tiers of backups:
- Tier 1 - production critical
- Tier 2 - Exhange & SharePoint
- Tier 3 - Other production
- Tier 4 - Development & test
Each storage policy has:
My Media agent has:
Max parallel Data transfer operations=100
My current media agent has:
Mount Path Allocation=Max allowable writers
I don't know what the value is for "Max allowable writers" so I'll take a guess and say that it is 10.
If all four tiers of backups are running, I'm could be allocating 200 device streams. If I have 15 mount points times 10 writers then the disk writers max out at 150. Finally, the media agent is set to 100 max parallel data transfer operations so this is my limiting factor.
On the new hardware, if I drop to 4 mount points, I've effectively dropped the max number of writers to 40 and introduced a bottleneck. It seems I need to keep at least 10 mount points to keep the number of writers in line with the configuration of the Media Agent.
This math is dependent on the maximum number of writers per mount path actually being equal to 10. If it is only 5 then any reduction in the number of mount points will decrease my throughput. Is there a way to determine how many writers per mount point I am actually getting?
Also, my backups ar 79% Windows File System, 19% Virtual servers and 2% Exchange. I don't think this impacts the allocation but thought I'd mention it.