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Cisco MDS 9500 Series Multilayer Directors

Field Notice: FN - 63157 - In Rare Situations Repeated show tech Commands May Cause an MDS Supervisor to Reboot When Running San OS 3.0(x) to 3.1(x)

Field Notice: FN - 63157 - In Rare Situations Repeated show tech Commands May Cause an MDS Supervisor to Reboot When Running San OS 3.0(x) to 3.1(x)

September 9, 2008


NOTICE:

THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE FIELD NOTICE OR MATERIALS LINKED FROM THE FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.

Revision History

Revision Date Comment
1.0
09-SEP-2008
Initial Public Release

Products Affected

Products Affected
M9500 - DS-X9530-SF1-K9
MDS9000 - DS-X9530-SF2-K9

Problem Description

In rare cases, MDS supervisor modules running the noted versions of SAN-OS can reboot when running the commands listed below:

Command First SAN-OS Fixed SAN-OS
show tech-support details
3.0(1)
3.3(1a)
show tech-support
3.1(1)
3.3(1a)
show tech-support cfs
3.1(1)
3.2(3a)
show tech-support cfs name
3.1(1)
3.2(3a)
show cfs internal message-context name
3.1(1)
3.2(3a)
show tech-support internal module x
3.0(1)
3.3(1b)
show system internal fcfwd idxmap interface-to-port
3.0(1)
3.3(1a)
show system internal fcfwd idxmap port-to-interface
3.0(1)
3.3(1b)

Care should be taken when running these commands on any affected version of SAN-OS. In rare situations, running these commands back to back in a dual supervisor configuration, the switch may reload. A single supervisor configuration is significantly more risky due to the inability to failover.

Background

Switch reloads due to execution of these commands are a rare occurrence, but may occur. The likelihood of a system reload will increase the more the commands are executed.

The show tech-support command is a compilation of other commands. Among those commands are the commands that include show system internal fcfwd... commands. The root cause of the problem is related to the "fcfwd" show commands.

Note: show tech-support details and show tech-support are the same command for SAN-OS 3.1(1) and higher.

Problem Symptoms

The MDS may reload when issuing one of the aforementioned commands. Care should be taken when running these commands on any affected version of SAN-OS.

Workaround/Solution

Temporary Workaround:
The user should also avoid running any of the affected commands. If a show tech-support output is required, open a case with the Cisco TAC. The TAC has a script that can be run which will avoid the "fcfwd" commands.

Permanent Fix:
The issue with the CFS and related commands is resolved in SAN-OS 3.2(3a) and higher.

The issue with the "fcfwd" and related commands is resolved in SAN-OS 3.3(1c) and higher.

SAN-OS 3.2(3a) and 3.3(1c) are available through the Software Downloads section of http://cco.cisco.com. Check with your provider for an approved version of SAN-OS for your environment.

DDTS

To follow the bug ID link below and see detailed bug information, you must be a registered customer and you must be logged in.

DDTS Description
CSCsi87843 (registered customers only) MDS SAN-OS 3.1(2b) CFS cores due to double-free/ memory corruption.
CSCso63759 (registered customers only) Switch reboots while running cmd "sho sys int fcfwd idxmap"

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

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