Here are some SQL commands that may come useful if you are looking for a specific VM when vCenter server goes down. You can run a SQL query to find a VM directly in the database. It will tell you which ESXi host the VM was last on so that you can connect directly to the host and open a console to the server.
List Hosts by ID
select * from VPX_ENTITY where type_id=1
LIST VM’s regeisterd to a host based on the id, change 47 to the host id
select vm.id,ent.name,vm.host_id from vpx_vm as vm left join VPX_ENTITY as ent on vm.id = ent.ID where vm.host_id = 47
List VM’s (Change HOST_ID last line to match host)
Select vm.ID,ent.NAME,vm.HOST_ID,vm.IP_ADDRESS
FROM VPX_VM AS vm LEFT OUTER JOIN
VPX_ENTITY AS ent ON vm.ID = ent.ID
WHERE (vm.HOST_ID = 101)
Another version of it
Select vm.ID,ent.NAME,vm.HOST_ID,vm.IP_ADDRESS,vm.DNS_NAME,vm.GUEST_OS,vm.GUEST_FAMILY,vm.BOOT_TIME,vm.LOCAL_FILE_NAME
FROM VPX_VM AS vm LEFT OUTER JOIN
VPX_ENTITY AS ent ON vm.ID = ent.ID
WHERE (vm.HOST_ID = 64)
List VM based on VM ID
Select vm.DNS_NAME,vm.ID,vm.LOCAL_FILE_NAME,ent.NAME,vm.HOST_ID,vm.IP_ADDRESS,vm.GUEST_OS,vm.GUEST_FAMILY,vm.BOOT_TIME
FROM VPX_VM AS vm LEFT OUTER JOIN
VPX_ENTITY AS ent ON vm.ID = ent.ID
WHERE (vm.ID = 67)