I have a question regarding storage maintenance.
If an ESX (3.5u4) Farm is connected to 2 different fiber based SANs, is it then possible to close down one SAN for maintenance (powering down the VMs on that SAN first of course)?
ESX installation is on local disks.
My reason for asking is that we actual tried this once, but it introduced some problems at the time. One of the problems that I remember was that we saw incorrect status of VMs in virtual center afterwards.
Maybe there is a supported procedure on doing this?
In our worst case (SAN crashed) after a rescan all disabled Storages are show grayed out. After the fix a next rescan put them back with all VMs to normal mode.
So if you power down all VMs and shutdown the SAN, just make an rescan.
But keep in mind thats not a "clean" way to do this.
For complete safety, i would hang out all storage areas which are in maintenance and hang them back after all (move your shutdown VMs to the other Storage area).
The other way round would be;
1. Shutdown the VM's.
2. Remove teh VM's from teh inventory.
3. Take downt eh storage for maintainence.
4. Once complete, rescan the storage adapter and make sure the data stores are displyed correctly on the Cluster.
5. Re-register teh VM's on the host back.
This makes sure that the VC would not show up any error for the VM's; even if this is not done the VM's would be in "inaccesible' state and once the storage is mounted back on the VC we it will be back to the correct state in some time.
With Storage VMotion, if you have the VMotion license (or you are in evaluation mode), you can do it without power-off the VM.
I was really interested in doing it without storage vMotion because it's not at problem to shutdown the machines on the datastore that belongs to the LUN we need do take down for maintenance - but we have lots of machines running on other LUNS that we would like to keep running