Hi there!
First thank to all for this great community!
I am configuring a small vSphere 5.5 cluster, and everything seems to be ok, but I have some doubts that I will want to share. The configuration is the following:
vSphere 5.5u2 hosts with two single Emulex HBAs 8G. (Host_HBA1 and Host_HBA2)
Netapp E2724 dual controller FC 8G (two ports per controller) and in theorytically active-active configuration. (Controller1_Port1, Controller1_Port2, Controller2_Port1, Controller2_Port2)
Two Brocade s300 switches with single initiator, multiple target zoning (Switch1: Host_HBA1 to Controller1_Port1 and Controller2_Port1 and Switch2: Host_HBA2 to Controller1_Port2 and Controller2_Port2)
Cabling seems to be correct and vSphere detects 4 paths per LUN, sets the multipath driver automatically to round robin, and sets two Active (I/O) paths and the other two only as Active.
The LUNS in the Netapp are configured as VMware O.S. LUNs (they are Dinamic Disk Pools Volumes) and AVT seems to be enable for this kind of Hosts.
Well, I tried different tests (Storage VMotion between different LUNs, VMware IO analyzer, to create and remove virtual machines...) and everything seems to run smoothly. The only strange behavior that I have noticed is that when one creates the volumes in the Storage system, they are assigned to one or other controller, and they have a "Preferred Owner" (Should this happen in a theoretically Active/Active Storage?). When for example, I make a storage VMotion between two DataStores (I have one DataStore per LUN) and this LUNS have different "preferred" controllers (LUN1 in Controller1 and LUN2 in Controller2) I have noticed that the LUN2 is automatically moved to the Controller1. I am not sure if this is a normal behavior to improve the performance or I have some misconfiguration (I have a message in the NetApp storage log that states: I/O shipping implicit volume transfer, and afterwards an alarm that the LUN is not in the preferred controller). I guess the multipath driver is using AVT to send the LUN to the same controller, but as I have said, I am not sure if this is normal. It would be nice if somebody can clarify this. The Storage VMotion finish well and no disk problems appears.
Thanks again for your time!