Re: 1.  I would suggest you keep them at two pools.  Only because of the size difference between the 6500's and 6100s.   You could go to 3 pools, but they you do run the risk of having to move VMs between them to balance IO.   Re:2.  I would also try turning off LRO,  Large Recieve Offload.   Re: 3. Upgrades.  Low I/O means when the array isn't being heavily used.  So yes, a low I/O reading from SANHQ would show that.  If your business isn't active 24x7 then it's the normal after hours weekend time frame.   Most important is setting the login_timeout to 60 on ESXi servers, and setting the disktimeout value to 60 in the VMs.  With recent firmware the time it takes to failover and start responding is usually under 30 seconds.  But not always, an can be nearer to 60 seconds under load.  Also critical is to make sure the switch ports come up immediately on transistion.  (AKA portfast)   This way when the CM fails over,  the ports come online right away.    Also, being able to handle a FW upgrade also means you can handle a CM failover on a HW problem.    Disk FW upgrades.   Yes.  The upgrades are done one drive at a time.   Then the drive is power cycled, to update the FW.   That time is very quick, and only I/O to that drive is paused, then resumed once the drive comes back online.   But again, best time is low I/O.  In a perfect scenario, yes doing upgrades in a Maint window would be ideal.  At least shutting down the VMs.   In that off chance something unexpected happened.  Since this is ESXi are you running at least 6.0.7 firmware?  Regards, 
I have 2 6500ES's and 1 6100XS being utilized by 8 ESX hosts running about 130 VM's.  Performance is important, but I just migrated my MD3000i data onto the 6500's, so I'm already seeing an improvement...the SSD's are awesome.  :) I have 3 questions 1.)  Should I make 1 Pool or 2?  I currently have them in 2 pools, however, I am wondering if just making 1 pool and letting the EQL load balancers do all of the guess work for me... I don't want to have to check IO usage between pools like I have been and manually or using storage DRS if I don't have to. IO based storage DRS requires turning on storage IO control, which is not best practice according to the EqualLogic VMWare Best Practice Documentation - I'm guessing because it could hinder the SAN's load balancer decisions. I believe I read that best practice says 2 pools, but I don't know if it takes 3 hybrids into consideration. With the exception of the VM's our data is pretty transient. We receive a small amount of data, create a large amount of data, duplicate it, back it up, deliver it, then it sits for a period of time before getting archived & purged. 2.)  I am seeing higher than expected read latency on the 6500's when IOPs drop below 500/sec.  it's not crazy high, but hovers around the 8ms range.  I turned off delayed ACK which brought the latency down from 12-15, and want to turn off TCP offloading next maintenance window.  But, is this normal?  My 6100 usually stays below 2ms read and write 3.)  Firmware updates - is it safe to do while there is activity? Or do I really need to shutdown all of my ESX hosts before doing it?  The documentation says to do it when there is low utilization... Does that mean that status in SAN HQ says low? or what is considered low? Does the same apply for the hard drive firmware updates? Thanks in advance!David
Storage Pools 3 Hybrid Arrays