Sun Storage 3510 FC Array: Getting Command Timeouts for LUNS in a SAN Configuration

Asset ID:	1-72-1003484.1
Update Date:	2010-07-16
Keywords:

Solution Type Problem Resolution Sure

Solution 1003484.1 : Sun Storage 3510 FC Array: Getting Command Timeouts for LUNS in a SAN Configuration

Applies to:

Sun Storage 3510 FC Array
Sun Storage SAN Software - Version: 4.0 and later ]
All Platforms

Symptoms

{SYMPTOM}
Symptoms

The specific loop configuration of a Sun Storage 3510 FC Array might
cause attached hosts to experience excessive SCSI timeouts, when a single
host is rebooted.

If this occurs, messages similar to the following message
appear in the "/var/adm/messages" file of the other hosts when one of
the hosts is rebooted:

Apr 27 nsvr-88 /scsi_vhci/ssd@g600c0ff00000000000272a68ad13490a
(ssd75): Command Timeout on path /pci@1e,600000/SUNW,qlc@4,1/fp@0,0 (fp3)

Changes

{CHANGE}

This issue only occurs when the Sun Storage 3510 FC Array is
configured in loop mode in a storage area network (SAN) configuration
with more than one host accessing the same Sun Storage 3510 FC Array.
The configuration affected by this problem is the "High performance
SAN configuration" mentioned in the Sun document 816-7325, which
is the "Sun StorEdge 3000 Family Best practices Manual."

In such a configuration, if you have multiple hosts accessing the logical
unit numbers (LUNs) for the Sun Storage FC Array, when one of the hosts is
rebooted, all the other hosts start getting SCSI timeouts and all the
applications might appear to be hung.

Cause

{CAUSE}

The problem was resolved in the 4.11 Controller Firmware in Release:
113723-10, but it is recommended to install the latest Controller Firmware
Release (4.2x in 113723-21 or later).

Solution

To recover from the described issue power cycle the array or fail/unfail the controller on the Sun Storage 3510 FC Array.

Workaround

Change from loop mode to fabric point-to-point mode on the Sun Storage 3510 FC Array:

1. Telnet to the Sun Storage 3510 FC Array.

2. Select the following from the menu:

View and Edit Configuration Parameters ----> Host-side SCSI Parameters ----> Fiber Connection Option - Loop only

3. Change Fiber Connection Option - "Loop only" to "Point to Point only".

4. Reset and re-map the channels and luns on the array.

Additional Information

A Sun Alert was also released for this problem. Please check Alert 1001226.1:
"Sun Storage 3510 FC Array in Loop Mode May Cause Attached Hosts to
Experience Excessive SCSI Timeouts Upon a Reboot".

See bug Ids 5038863 and 5061098.
Change History
Date: 2010-07-16
User Name: [email protected]
Action: Update & Currency

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