VMWare can't map datastore after controller failure or replacement

# esxcfg-volume -l
Scanning for VMFS-6 host activity (4096 bytes/HB, 1024 HBs).
VMFS UUID/label: 5c376ada-69ba365e-a230-4c52621182c2/esxi3-1
Can mount: Yes
Can resignature: Yes
Extent name: t10.ATA_____ST1000NM00552D1V410C_________________________________ZBS1ENA8:3    range: 0 - 945663 (MB)


# esxcli storage vmfs snapshot list
5c376ada-69ba365e-a230-4c52621182c2
   Volume Name: datastore2
   VMFS UUID: 5c376ada-69ba365e-a230-4c52621182c2
   Can mount: true
   Reason for un-mountability:
   Can resignature: true
   Reason for non-resignaturability:
   Unresolved Extent Count: 1


esxcli storage vmfs snapshot mount -l "datastore2"

 

Now rescan your datastores and it should be there.

 

Otherwise check the full VMWAre article:
https://kb.vmware.com/s/article/2014155