My AIX client LPAR has error ED995F18 VSCSI_ERR3 logged against my vscsi client adapter.

The DVD-RAM drive is the ONLY backing device mapped through a vhost to a vscsi client adapter. Then cd0 backing device is removed from the vhost adapter that is mapped to the vscsi adapter before removing the vscsi client adapter and cd0 from the ODM definitions on the client LPAR.

To properly move a DVD-RAM drive from a client LPAR to another client LPAR when the DVD-RAM is the only backing device of the vhost adapter that is mapped to the owning client LPAR’s vscsi client adapter, you must first remove the cd0 and vscsi client adapter definitions from the owning LPAR’s ODM.

Example:

VIO1, vhost2 (V1-C12) is mapped to LPAR ID 3, vscsi2 (V3-C99)

(V3-C99) is mapped backed to VIO1, vhost2 (V1-C12)

cd0 is the ONLY backing device for vhost2:
$ lsmap -vadapter vhost2
SVSA Physloc Client Partition ID
————— ——————————————– ——————
vhost0 U9111.520.104797E-V1-C12 0×00000003

VTD vtopt0
LUN 0×8200000000000000
Backing device cd0
Physloc U787A.001.DPM06E2-P4-D2

If cd0 is removed from vhost2, this will cause the VSCSI_ERR3 on client LPAR ID 3 because the system assumes the device is lost and therefore, the vscsi path is now in a defined state and no longer available.

# lsdev -Cc adapter

vscsi2 defined

To prevent this error, you must first remove the ODM device definitions from the client LPAR before you remove cd0 from vhost2 :

# rmdev -Rdl vscsi2

Once the cd0 and vscsi2 device definitions are removed from the client LPAR’s ODM database, the vscsi path is no longer “live” or mapped and the cd0 backing device can now be moved to another vhost without causing the ED995F18 VSCSI_ERR3 errors to be logged on the client LPAR ID 3.