Fabric Interconnect

Locked Out of Cisco UCS? How to Recover the Master Admin Password | Lazy Admin Blog

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It’s the nightmare scenario: you need to make a critical service profile change, but the only admin password is lost or forgotten. Because Cisco UCS Manager doesn’t store passwords in a reversible format, you can’t “view” the old one. Instead, you must perform a password reset by power-cycling the Fabric Interconnects (FIs) and interrupting the boot sequence.

⚠️ Warning: This procedure requires a physical power cycle of the Fabric Interconnects. In a production environment, this will cause a temporary disruption in management connectivity and potentially data traffic if not handled correctly in a cluster.

Phase 1: The Pre-Flight Check

Before you pull the power cables, you need two pieces of information. If you still have read-only access or a lower-privilege account, gather these now:

  1. Identify the Roles: In a cluster, you must know which FI is Primary and which is Subordinate.
    • Path: Equipment > Fabric Interconnects > [FI Name] > General > High Availability Details.
  2. Verify Firmware Versions: You must know the exact Kernel and System firmware versions currently running.
    • Path: Equipment > Firmware Management > Installed Firmware.

Phase 2: Password Recovery (The Process)

Scenario A: Standalone Configuration

If you only have one Fabric Interconnect, the process is straightforward but requires downtime.

  1. Connect: Attach a console cable physically to the FI console port.
  2. Power Cycle: Turn the FI off and then back on.
  3. Interrupt Boot: As it boots, repeatedly press Ctrl+L or Ctrl+Shift+R until you see the loader > prompt.
  4. Boot Kernel: Load the kickstart/kernel image: loader > boot /installables/switch/ucs-6100-k9-kickstart.x.x.x.gbin
  5. Enter Config: Fabric(boot)# config terminal
  6. Reset Password: Fabric(boot)(config)# admin-password YourNewPassword123
  7. Load System: Exit config mode and boot the system image: Fabric(boot)# load /installables/switch/ucs-6100-k9-system.x.x.x.bin

Scenario B: Cluster Configuration (High Availability)

In a cluster, the order of operations is vital to ensure the database remains synchronized.

  1. Subordinate First: Power cycle the Subordinate FI and interrupt its boot to the loader > prompt. Leave it there.
  2. Primary Second: Power cycle the Primary FI and interrupt its boot to the loader > prompt.
  3. Reset on Primary: Follow the “Standalone” steps (4 through 7) on the Primary FI console.
  4. Bring up Subordinate: Once the Primary is back up and you can log into UCS Manager, go to the Subordinate console and boot its kernel and system images normally from the loader prompt.

Important Notes

  • Clear Text: When you type the admin-password command in the boot loader, the password displays in clear text on the screen. Ensure no one is shoulder-surfing!
  • Strong Passwords: UCS Manager requires at least one capital letter and one number.
  • Console Access: This cannot be done via SSH. You must have physical or terminal server access to the console port.

#CiscoUCS #DataCenter #CiscoProphet #SysAdmin #Networking #ITTech #Cisco #UCSManager #LazyAdmin #Infrastructure

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🏗️ CLI Command Hierarchy & Navigation

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The CLI is organized like a file system. You move “down” into specific modes to manage objects and “up” to return to the global level.

  • EXEC Mode (#): The top-level mode. From here, you can access all other sub-modes.
  • Navigation Commands:
    • scope <object>: Moves into a sub-mode for an existing object (e.g., scope chassis 1).
    • enter <object>: Similar to scope, but used to enter or create an object’s mode.
    • exit: Moves up one level in the hierarchy.
    • top: Jumps immediately back to the EXEC mode prompt.

🛠️ Common Management Commands

TargetCommandPurpose
Chassisshow chassis [inventory/status/psu]View physical chassis health and components.
Serversshow server [inventory/cpu/memory/status]Audit blade or rack-mount hardware specs.
Fabricshow fabric-interconnect [a/b] [inventory]Check the state of your Fabric Interconnects.
Faultsshow fault [detail/severity]List active system alarms and errors.
Logsshow sel [chassis-id/blade-id]View the System Event Log for specific hardware.

💾 The Transactional Model (Commit Buffer)

Unlike many traditional CLIs, UCS Manager uses a transactional model. When you make a configuration change (like set or enable), the change is stored in a temporary buffer and is not live until you explicitly save it.

  1. Modify: set addr 192.168.1.50
  2. Verify: show configuration pending (Optional)
  3. Apply: commit-buffer
  4. Discard: discard-buffer (If you made a mistake)

#CiscoUCS #CommandLine #SysAdmin #DataCenter #Networking #Cisco #ITPro #LazyAdmin #TechTutorials #UCSM

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