Solaris 11.4 Command Timeout On Path To Dell EMC SYMMETRIX VMAX3 and VMAX All Flash 16Gb Fibre Channel I/O Module For NULL WRITE (Doc ID 2623057.1)

Last updated on OCTOBER 16, 2023

Applies to:

Solaris Operating System - Version 11.4 and later
Information in this document applies to any platform.

Symptoms

A server running Solaris 11.4 encounters Command Timeout on path to Dell EMC SYMMETRIX VMAX3 and VMAX All Flash 16Gb Fibre Channel I/O Module for NULL WRITE. For example:

SCSI Block Commands (SBC-3), Clause 5 Commands for direct-access block devices, Chapter 5.33 WRITE(10) command:

The TRANSFER LENGTH field specifies the number of contiguous logical blocks of data that shall be transferred from the Data-Out Buffer and written, starting with the logical block specified by the LOGICAL BLOCK ADDRESS field. A TRANSFER LENGTH field set to zero specifies that no logical blocks shall be written. This condition shall not be considered an error.

A NULL WRITE command should trigger reservation conflict status response according to SCSI Primary Commands (SPC) in any other case than the Initiator Target (I_T) nexus has an active reservation. TEST UNIT READY (TUR) should not do so in SPC-3, although it was supposed to trigger reservation conflict in SPC-2.

SCSI Primary Commands (SPC-3), Clause 5 Model common to all device types, Chapter 5.6 Reservations, Section 5.6.1 Persistent Reservations overview:

**Table 31 — SPC commands that are allowed in the presence of various reservations**
Command	Addressed logical unit has this type of persistent reservation held by another I_T nexus
	From any I_T nexus		From registered I_T nexus (RR all types)	From not registered I_T nexus
	Write Excl	Excl Access		Write Excl RR	Excl Access – RR
TEST UNIT READY	Allowed (b)	Allowed (b)	Allowed	Allowed (b)	Allowed (b)
WRITE BUFFER	Conflict	Conflict	Allowed	Conflict	Conflict
Key: Excl=Exclusive, RR=Registrants Only or All Registrants, <> Not Equal
(a) Exceptions to the behavior of the RESERVE and RELEASE commands described in SPC-2 are defined in 5.6.3. (b) Logical units claiming compliance with previous versions of this standard (e.g., SPC-2) may return RESERVATION CONFLICT in this case.

SCSI Primary Commands (SPC-2), Clause 5 Model common to all device types, Chapter 5.5 Reservations, Section 5.5.1 Reservations overview:

**Table 10 — SPC commands that are allowed in the presence of various reservations**
Command	Addressed LU is reserved by another initiator [A]	Addressed LU has this type of persistent reservation held by another initiator [B]
		From any initiator		From registered initiator (RO all types)	From initiator not registered
		Write Excl	Excl Access	From registered initiator (RO all types)	Write Excl RO	Excl Access – RO
TEST UNIT READY	Conflict	Conflict	Conflict	Allowed	Conflict	Conflict
WRITE BUFFER	Conflict	Conflict	Conflict	Allowed	Conflict	Conflict
Key: LU=Logical Unit, Excl=Exclusive, RO=Registrants Only, <> Not Equal