VMware Tape Drive pass-through

If a tape drive comes up with VMW_SATP_ALUA rule in VMware vShpere (4.0 or later) you will most likely see input/output errors during backup operation on the VM you mapped to drive to. A working rule is VMW_SATP_LOCAL and you can change it using some simple steps.

  1. Find the module for SCSI/SAS HBA using esxcfg-scsidevs
    esx# esxcfg-scsidevs -a
    vmhba0 cciss link-n/a block.cciss/c0d0:0 (0:2:1.0) Compaq Computer Corporation Smart Array P400
    vmhba1 mptspi link-n/a pscsi.vmhba1 (0:7:1.0) LSI Logic / Symbios Logic ProLiant
    vmhba2 mptspi link-n/a pscsi.vmhba2 (0:7:1.1) LSI Logic / Symbios Logic ProLiant
  2. Add an additional rule for the HBA module the tape drive/changer is attached to
    esx# esxcli nmp satp addrule --satp VMW_SATP_LOCAL --driver="mptspi" --description="Tape drive support"
  3. Restart the ESX host to activate changes. The drive will now work as expected.
  4. Map the tape drive according to http://kb.vmware.com/kb/1016407

Note: As this issue is related to the HBAs and tape drvies/changers used not all environments are affected.

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