Less than three weeks after getting all the Equallogic arrays up to the latest firmware while making the most of a power failure down time along comes another firmware update!
The Equallogic arrays have two controllers each with redundant network connections for SAN traffic. One controller is the active controller and the other is the passive standby.
During updates both controllers are flashed with the new firmware. The standby controller is restarted which does not affect traffic but brings it online with the new firmware. The active controller is then restarted which causes the standby controller to take over as the active controller (are you following this???) and the old active controller then restarts with the new firmware in the standby role.
So, the theory is that the time taken to fail over the controller is less than the iSCSII timeout of connected systems so there is no interruption to disk I/O… With ~50 systems running in the environment including a bunch of GroupWise post offices it takes some faith that this will in fact work as described.
When I introduced the new PS6010X 10 GbE array I put it in a separate group and moved a few low impact systems to it as an initial test. I then moved the new ADM4PO post office server to the new group to flex it a little more.
With fingers crossed I performed the firmware upgrade on the new array. There are a few heart stopping moments as connections are lost and reconnected and various components start generating alerts and flashing red warnings! The whole process took a few minutes but worked flawlessly. My own mailbox is on the ADM4PO and I was able to keep working throughout. I also monitored all 8 VMs running from the array through vCenter and not one alert was generated.
The question now is – Do I have the nerve to perform the same upgrade on the older arrays?
