Frequent ScsiDeviceIO failed logs on vmkernel logs of ESXi

Products

• VMware vSphere ESXi

Issue/Introduction

On ESXi hosts connected with local datastore below logs were observed in vmkernel logs frequently 

xxxx-xx-xxTxx:xx:xx.xxxZ cpu3:xxxxxxx)ScsiDeviceIO: 3484: Cmd(0xxxxxxxxxxxxx) 0x85, CmdSN 0xa465 from world xxxxxxx to dev "naa.xxxxxxxxxxxxxxxxxxxxxxxxxxxxx" failed H:0x0 D:0x2 P:0x0 Valid sense data: 0x5 0x20 0x0.

Environment

ESXi (All Versions)

Cause

These messages are not errors but information returned from SAN / LUNs. SCSI errors or warnings in ESXi are displayed with 6 status codes. The decoding of the information H:0x0 D:0x2 P:0x0 Valid sense data: 0x5 0x20 0x0  is as below

• Host Status [0x0] OK This status is returned when there is no error on the host side. This is when you will see if there is a status for a Device or Plugin. It is also when you will see Valid sense data instead of Possible sense Data.
• Device Status [0x2] This status is returned when a command fails for a specific reason. When a CHECK CONDITION is received, the ESX storage stack will send out a SCSI command 0x3 (REQUEST SENSE) in order to get the SCSI sense data (Sense Key, Additional Sense Code, ASC Qualifier, and other bits). The sense data is listed after Valid sense data in the order of Sense Key, Additional Sense Code, and ASC Qualifier.
• Plugin Status [0x0] GOOD No error. No error. (ESXi 5.x / 6.x only)
• Sense Key [0x5] ILLEGAL REQUEST
• Additional Sense Data 20/00 INVALID COMMAND OPERATION CODE

 Below URL converts these sense codes from ESXi Hosts to human readable status information.

VMware ESXi SCSI Sense Code Decoder

 

 

Resolution

These messages not are errors but information returned from SAN / LUNs. 

Additional Information

Refer community page for more information VMware community page for valid sense data

Refer KB 337796 for more information