I have an MD3000i Dell SAN with dual controllers. Long story short - it managed to muck up some of its own readings on drives and Dell's support told me I could try to shake it loose with a firmware and NVSRAM upgrade which I need anyway. Since I have a dual controller this can apparently be done live and the upgrade process handles shuffling LUNs between controllers as it updates.
Does anyone have experience with this? The Dell technician claimed it could be done and the documentation suggests as much for dual-controller configurations, but it makes me very nervous to do it.
My main questions are:
- Has anyone done this successfully or know someone who has?
- Are there any pitfalls to be aware of?
I have successfully performed an update like this on thea same hardwareway for very similar reasons on a couple occasions. My experience was good and required no down time, although it was restricted to a couple esx 3 hosts. Definitely need to have good backups and execute during a maitainance window.
Just last night I had a bad firmware update for my HP san and it took three hours to get it cleared up. That included over an hour of downtime for all VMs using this storage.
I have tried replacing san controller 2 times, 1 good 1 bad.
The first time was with a vsphere cluster, the second time with an oracle failsafe windows cluster.
Both maintenances involved replacing controller, and syncing controller firmware (upgrading firmware on the old controller with the one on the new).
The first time, everything went very smoothly.
The second time, although during the upgrade process no san path was lost, all luns were visible all the time. somehow oracle failsafe was triggered, and primary server tried to transfer role to secondary server but failed, secondary server failed to detected this and pick up the database, resulted a service suspension.
The cause of the second case was still unclear, although misconfiguration on cluster software was one of the possibilities. I would definitely recommend a maintenance windows, just for the sake of stability.