Using Tape drive as SCSI passthru, rather than whole controller.
Often causes glitches such as tape drive going offline after backup etc.
Possible solution, from https://communities.vmware.com/thread/334987 is:
Verify if the tape drive is using VMW_SATP_AULA (which is bad)
SSH into esxi 5 console
esxcli storage nmp device list
naa.500110a0014b774a
Device Display Name: HP Serial Attached SCSI Tape (naa.500110a0014b774a)
Storage Array Type: VMW_SATP_ALUA
Storage Array Type Device Config: {implicit_support=on;explicit_support=off; explicit_allow=on;alua_followover=on;{TPG_id=0,TPG_state=AO}}
Path Selection Policy: VMW_PSP_MRU
Path Selection Policy Device Config: Current Path=vmhba2:C0:T0:L0
Path Selection Policy Device Custom Config:
Working Paths: vmhba2:C0:T0:L0
Note: View the Storage Array Type
To change this to VMW_SATP_LOCAL
esxcli storage nmp satp rule add --satp=VMW_SATP_LOCAL --vendor="HP" --model="Ultrium 5-SCSI"
Next you need to remove any claims to that device
esxcli storage core claiming unclaim -t location -A vmhba1 -C 2 -T 0 -L 0
(your vmbha must match!)
esxcfg-rescan vmhba1 esxcli storage nmp device list
Reboot esxi host
Then add your Tape via SCSI device in the VM settings
