PowerPath Enabled Hosts Report "Illegal Request" for Opcode 0xC3

Summary: Hosts with PowerPath installed over FC may receive an "Illegal Request" message for the 0xC3 opcode, which may repeat every 10 seconds.

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Symptoms

  • Hosts with PowerPath installed over Fibre Channel (FC) may display an "Illegal Request" message for opcode 0xC3
  • The message may repeat approximately every 10 seconds, creating frequent log entries
  • No functional impact is observed on I/O operations, but the repeated messages can clutter system logs and monitoring tools

 

Example host side message (RHEL):

Nov  4 16:56:37 trctr002 kernel: sd 16:0:2:5: [sdx] tag#4952 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE cmd_age=0s
Nov  4 16:56:37 trctr002 kernel: sd 16:0:2:5: [sdx] tag#4952 Sense Key : Illegal Request [current]
Nov  4 16:56:37 trctr002 kernel: sd 16:0:2:5: [sdx] tag#4952 Add. Sense: Logical unit not supported
Nov  4 16:56:37 trctr002 kernel: sd 16:0:2:5: [sdx] tag#4952 CDB: opcode=0xc3 (vendor) c3 00 01 00 00 00 00 00 00 00

Cause

The vendor-specific SCSI command "PowerPath Ping" (opcode 0xC3) was introduced in PowerStoreOS version 3.0 and later. PowerPath uses this command to evaluate SAN latency on PowerStore arrays.
Due to a software issue in the implementation of the 0xC3 command within PowerStoreOS 3.x releases, the command issued by PowerPath over Fibre Channel may fail on certain operating systems, such as Windows and RHEL 8.

Resolution

The issue is resolved in PowerStoreOS version 4.0 and later.
Upgrading the array to PowerStoreOS to latest LTS release ensures proper handling of the PowerPath Ping (opcode 0xC3) command, eliminating the repeated "Illegal Request" messages.

Affected Products

PowerStore
Article Properties
Article Number: 000414264
Article Type: Solution
Last Modified: 14 يناير 2026
Version:  2
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