Cisco switch: MDS 9700 Standby supervisor in reboot loop

Summary: During upgrade, standby supervisor goes into reboot loop - manual power-off/on of standby supervisor required to recover.

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.
Check out other resources

Symptoms

In Service software upgrade [ISSU] started

During NX-OS ISSU upgrade, the standby supervisor goes into reboot loop.
From the console, it can be observed: the supervisor was trying to mount a USB device, and once entering run level 3 it reboots again.

Exception log message:

0x40c90000 Not able to mount filesystem on OBFL flash Error Description: Not able to mount filesystem on OBFL flash Logging log streaming errors: %USBHSD-STANDBY-2-MOUNT: logflash: Online %PLATFORM-2-MOD_REMOVE: Module X removed (Serial number XXXXXXXXXXXX)

 

Cause

The standby supervisor is trying to mount a USB device, and once entering run level 3 it reboots again.
0x40c90000 Not able to mount file system on OBFL flash Error Description: Not able to mount file system on OBFL flash.

 

Resolution

From an active supervisor:

  1. Out of service module X [where X is the standby supervisor]
  2. No power-off module X
  3. Confirm that the standby supervisor is HA standby using CLI: Show system redundancy status

Once standby supervisor has been recycled and is back in HA standby, you can proceed with the switch non-disruptive [ISSU] code upgrade.

 

Affected Products

Connectrix MDS-9710, Connectrix MDS-Series Firmware

Products

Connectrix MDS-9710, Connectrix MDS-Series Firmware 6.X, Connectrix MDS-Series Firmware 7.X, Connectrix MDS-Series Firmware 8.X, Connectrix MDS-Series Firmware 9.X
Article Properties
Article Number: 000064949
Article Type: Solution
Last Modified: 20 May 2026
Version:  4
Find answers to your questions from other Dell users
Support Services
Check if your device is covered by Support Services.