For a storage upgrade, I swapped out two HBAs, an SAS9341-8i (SAS3) and a Dell PERC H310 (SAS2). The 9341 was changed to a 9300-8i and the PERC was replaced with another 9300-8i.
The storage was acting as iSCSI targets for two ESXi datastores. For the LUN originally attached to the SAS2 card, the device could be seen in ESXi (under storage->devices) however the datastore would not mount. The datastore that was originally on the 9341 card was fine.
ESXi logs (monitor -> logs -> /var/log/vmkernel.log) showed that the device was “detected to be a snapshot.” VMware has as KB describing this problem where ESXi cannot confirm the identity of the LUN attached to the new SAS3 adapter.
https://kb.vmware.com/s/article/1011387
The steps used to fix the datastore that would not mount:
- Find the device
esxcli storage vmfs snapshot list - Resignature the device and mount
esxcli storage vmfs snapshot resignature -l “LABEL OF THE VMFS” - Check ESXi datastores (Storage-> datastores)
You should see it appear with a new name “snap-xxxx-LABEL OF THE VMFS” - Rename the datastore as appropriate
Notes: Registered VMs on that datastore had to be reregistered. Also VMs that used hard drives on that datastore had to updated in the configuration for the new signature.