JumpR wrote:
This is an important point. More LUNs = more devices = more queues = better response time (usually).
So does it mean that each LUN (aka SAN Datastore) is allocated a thread vs each individual vmdk inside the LUN? This way having a small number vmdk LUNs improves the performance.
Its not a thread, its a queue. There are many queues, including queues within the guest, within the VM, per VMDK, per LUN, per target, per HBA, etc.
is this I/O thread management done on the SAN side or ESX side? we have EqualLogic PS5000 and esx server 4.0.0. If on esx side does going to esx 5 improves the thread management?
Its both, because there are queues in both the array and the host (and the VMs)
In general, more LUNs gives (slightly) better performance. This quickly has diminishing returns however, so going from 1 LUN to 5 is very good. From 25-30 is probably nothing.