Get the SCSI ID:

xe sr-proble type=lvmohba 2>&1

Grab the id between <SCSIid> and </SCSIid>

Get the XenServer assigned device uuid:

xe sr-probe type=lvmohba device-config:device=/dev/disk/by-id/scsi-<your scsi id>

Introduce the existing SR to XenServer:

xe sr-introduce uuid=<your device uuid> shared=true type=lvmohba name-label="NewSR"

Get your host uuid-s:

xe host-list

Create a PBD for each host in the pool:

xe pbd-create sr-uuid=<your device uuid> device-config:device=/dev/disk/by-id/scsi-<your scsi id> host-uuid=<your host uuid>

Switch the connection on for each host:

xe pbd-plug uuid=<uuid from pbd-create command result>

You should now see the SR enabled in XenCenter and you can rescan it under Storage tab to show all existing virtual disks.