We are using the array for a VMware server farm and was wondering what a recommended configuration could be to minimize downtime in case of a lost DAE:
For example moving the disks:
dpe - 10 disks
dae - 9 disks
dae - 9 disks
Then create some RAID groups that use disks from each tray????? I know by default the RAID groups take the disks from the same tray.
if you look in VNX best practices document, there is actually a section for vertical provisioning. Other then some corner cases, it's not something that you MUST do and if you use virtual pools it does not matter anymore.
I strongly recommend to create Raid Group cross as many DAEs as possible. I have seen so many times the whole DAE drives dropped not ready due to LCC/Power/Loop issue. It's not a smart way to put all your eggs in same basket.
When I was in Symmetrix support team, I saw the whole DAE failed every day for variety of reasons. Sometimes the whole bus failed which includes 2 or 3 DAEs. Because Symmetrix always keep another datacopy on other bus, customer won't experience DA. I am always wondering why CLARiiON would select drives in the same DAE to form Raid Group by default. You can follow EMC BP. But if I have a CLARiiON, I won't create Raid Group on that way.
dynamox
11 Legend
•
20419 Posts
•
87439 Points
2141
0
Posted January 15th, 2012 18:00
if you look in VNX best practices document, there is actually a section for vertical provisioning. Other then some corner cases, it's not something that you MUST do and if you use virtual pools it does not matter anymore.