Today a power outage hit our datacenter for several hours. This was too long for the UPS so everything was shut down since we don’t have any backup generator or something like that. However when power came back on the ESX hosts booted faster as our storage controllers. I logged into VirtualCenter and I saw that none of my virtual machines were powered on automatically. They were greyed out with “(inaccessible)” behind the names. I googled, but couldn’t find anything related to my problem.
When I looked at the ESX hosts they weren’t showing my SAN datastores. So I went to my commandview EVA server and looked if the LUN’s were there. In fact first they weren’t there, but after a while they finally appeared. I turned back to my VirtualCenter and looked if the datastores also would appear automatically again, but that apparently was too much to ask. Not knowing what to do I started looking around what I could do. I looked at the storage adapter configuration of one of the ESX hosts and the HBA’s were nicely listed, but still no LUN’s. Finally just before I wanted to reboot the entire host I discovered I could rescan the HBA with right clicking on the HBA and then click “Rescan”. After the rescan was finished my datastores returned and I was back in business.
For the people who like to do everything at the commandline you can use the command:
esxcfg-rescan vmhba[0...n]
