Can anyone offer some suggestions please or simulate to see if this could also happen in your environment? Thanks!

We are currently testing the final switch and array redundancy now, we have performed every possible fail scenarios (on Switch, Switch Ports, LAN on ESX, ESX hosts etc), they all worked perfectly as excepted, EXCEPT ONE OF THE following situation.

This is how we performed the test:

1. Putty into ESX 4.1 host Service Console, then issue “vmkping 10.0.8.8 -c 3000″ where 10.0.8.8 is our group IP, it can ping it without problem.

2. Turn OFF the master PowerConnect 5448 swtich (where we have two PC5448, master and slave, no STP and all LAG/VLAN etc has been setup properly according to the guide/best practice and we have connected all the redundancy paths correctly between switches and ESX Hosts), then we see in vCenter the ESX 4.1 host, it shows 2 out of 4 ports failed with a red cross in iSCSI VMKernel vSwitch.

3. The “vmkping 10.0.8.8 -c 3000″ stopped working until we Turn On the the master PowerConnect 5448 swtich again.
Please note the following special findings:

a. Even we cannot ping to 10.0.8.8 from the ESX Host during master switch is off, but in EQL group manager, it is still showing the ESX Host CAN STILL ESTABLISH iSCSI connection to it, and all the VM on that ESX Host is working with no problem, and we can still do VMotion between ESX Hosts even with the master switch turned off. So the iSCSI connection is not dead, just cannot be pinged somehow from ESX Host.

b. We also performed ANOTHER SIMILAR test BY turning off individual array iSCSI ports on master switch, we used OpenMange to connect to the master switch, and then TURN OFF the TWO ports connecting to PS6000XV, so to PS6000XV active controller, it shows again 2 out of 4 ports failed with a red cross.

Please note to EQL PS6000XV active controller, they see 2 out of 4 ports failed, yes, BUT we used TWO different method to have the same goal (1st one is to turn off the whole switch, the 2nd one is to turn off the iSCSI ports connecting to the array on switch) In the 2nd case, “vmkping 10.0.8.8 -c 3000″ IS STILL WORKING! How come the 1st situation doesn”t work? So the conclusion is “vmkping 10.0.8.8 -c 3000″ WILL ONLY NOT WORKING when WE TURN OFF the master switch.