Upgrade/Datastore concern

[KenyonH]

Currently, we have a mixed environment with hosts ranging from 3.0.x to 3.5 Update4. We want to bring all hosts to 3.5. To complete this we plan on reinstalling the host, which are connected to a FC SAN. My question is this: When we reinstall the host with 3.5, will the newly installed host still be able to see the datastore. It will still be the same physical machine and the store will still be presenting the disks. HBA's and address will stay the same as well, so I'm thinking that we will just have to refresh/rescan the adapters once the new OS is installed so it can see the store. Is this correct? Or do we have to present the storage to the server again? I hope not because I'm obviously not the SAN admin, nor do we have one. We normally call support anytime we want to do anything with storage, which we do not want to do. Any help is much appreciated. Thanks.

[weinstein5]

Yes since nothing is changing hardware wise you should be able to see the existing datastores and make use of them from the new 3.5 servers and a rescan should not be necessary since the LUNs will be scanned when the ESX host boots - but when you do the reinstall I would disconnect the SAN from the host you are installing to so you do not accidentally select a LUN already in use -

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[jordan57]

I am doing the same thing on 35 hosts over the next couple of weeks. I have been doing it this same way. Migrate all the machines to another hosts place in Maint mode. Disconnect SAN and reinstall.

When you add it back into VC rescan and your good.

[AndreTheGiant]

Be sure to remove SAN connections (just unplug the fibre) during installation.

Then, when system reboot reconnect the SAN.

SAN switches and SAN storage configuration remain the same (cause is based on HBA WWN, and sometimes on ESX hostname/IP).

If you do not see the datastore, but you see the LUN (under storage adapter), just import the VMFS volumes.

Andre