Fast Track Mode

Overview

Fast Track mode is an optimization feature in CAPM3 that keeps BareMetalHosts powered on during machine deletion when certain conditions are met. This can significantly speed up cluster upgrades and node replacements by avoiding an extra power cycle before the host is re-used.

CAPM3 Fast Track is different from Ironic Fast Track. Ironic Fast Track reuses an already-running agent ramdisk across Ironic inspection, cleaning, and deployment. CAPM3 Fast Track controls whether CAPM3 leaves the BareMetalHost Online during Metal3Machine deletion. These features are commonly used together in Metal3, but enabling one does not enable the other.

How It Works

When a Metal3Machine is deleted, CAPM3 normally lets the BareMetalHost power off as part of deprovisioning. With Fast Track enabled, CAPM3 can keep the host powered on when automated cleaning is set to any value other than disabled.

When automated cleaning is enabled, the physical machine boots into the Ironic Python Agent to run cleaning. CAPM3 Fast Track keeps the machine running with the agent after cleaning completes, which saves one reboot when the host is re-provisioned.

The behavior is controlled by three factors:

1. BareMetalHost.Spec.DisablePowerOff: If true, the host always stays online (highest priority)
2. CAPM3_FAST_TRACK environment variable: Set to true or false
3. BareMetalHost.Spec.AutomatedCleaningMode: Set to disabled or a cleaning-enabled mode such as metadata

Behavior Matrix

Starting with CAPM3 v1.13.0, DisablePowerOff=true can be combined with AutomatedCleaningMode=metadata. In that case, DisablePowerOff still takes priority and keeps the host online.

The host remains online when:

• DisablePowerOff is true (takes priority over all other settings), or
• AutomatedCleaningMode is not disabled AND CAPM3_FAST_TRACK is set to true

When both conditions are met, the BareMetalHost remains powered on after the Metal3Machine is deleted, allowing it to be quickly re-claimed by a new Metal3Machine without waiting for a full power cycle.

When to Use Fast Track

Fast Track is beneficial in use cases where BareMetalHosts are expected to be re-used eventually and power consumption is not a factor, for example:

• Rolling upgrades: Nodes are being replaced one at a time, and speed is important
• Development/testing: Quick iteration cycles where full deprovisioning adds unnecessary delay
• Predictable host reuse: Reusing the same physical hosts is part of the normal operating model

Fast Track is less useful, or should be disabled, when:

• Hosts should remain powered off: Power consumption, cooling, or rack operations require unused machines to be off
• Physical maintenance is planned: Hardware replacement or other service work requires the machine to be powered off
• Automated cleaning is disabled intentionally: AutomatedCleaningMode=disabled makes CAPM3 power off the host

Configuration

Enabling Fast Track

Fast Track is configured via the CAPM3_FAST_TRACK environment variable on the CAPM3 controller. It defaults to false.

Via clusterctl

Add to your clusterctl configuration file:

variables:
  CAPM3_FAST_TRACK: "true"

Via Environment Variable

If deploying the controller directly, set the environment variable:

export CAPM3_FAST_TRACK=true

Configuring AutomatedCleaningMode

For Fast Track to work, automated cleaning must not be disabled. Today the documented CAPM3 cleaning-enabled value is metadata, and CAPM3’s deletion logic treats any value other than disabled as eligible for Fast Track.

In CAPM3 workflows, configure automated cleaning through the Metal3MachineTemplate or Metal3Machine fields described in the CAPM3 automated cleaning documentation, and let CAPM3 replicate the setting to the BareMetalHost. This can also be combined with DisablePowerOff=true; in that case DisablePowerOff remains the deciding factor for keeping the host online.

Behavior During Machine Deletion

When a Metal3Machine is being deleted:

1. CAPM3 clears the BareMetalHost’s image, customDeploy, userData, metaData, and networkData references
2. Based on the DisablePowerOff, AutomatedCleaningMode, and CAPM3_FAST_TRACK values, CAPM3 sets the BMH’s Online field:
   • Fast Track active: The host stays online (Online: true) while deprovisioning and cleaning complete
   • Fast Track inactive: The host is powered off (Online: false) as part of deprovisioning
3. CAPM3 waits for the host to reach an available state before fully releasing it
4. The ConsumerRef and other association data are cleared

Fast Track does not skip BMO or Ironic deprovisioning. It avoids the extra power-off and power-on cycle when a cleaned host will be re-used.

Monitoring

When Fast Track is active, CAPM3 produces log messages like:

Set host Online field based on DisablePowerOff, AutomatedCleaningMode, and Capm3FastTrack host=node-0 automatedCleaningMode=metadata hostSpecOnline=true

When Fast Track keeps a host online, the BareMetalHost still deprovisions and runs cleaning. The difference is that the host remains Online, so the next Metal3Machine can claim it without waiting for another power-on boot.

Troubleshooting

Host Not Staying Online

If hosts are being powered off despite Fast Track being enabled:

1. Verify CAPM3_FAST_TRACK is set to true (not True or 1)
2. Check that AutomatedCleaningMode is not disabled (metadata in current CAPM3 documentation)
3. Review controller logs for the decision logic

Host Stuck in Deprovisioning

If a host appears stuck, it may be waiting for cleaning to complete. Check:

1. The Ironic conductor logs for cleaning status
2. The BareMetalHost status for any error messages
3. Whether the host’s BMC is accessible

Related Documentation

• Automated Cleaning - Details on automated cleaning modes
• Baremetal Operator Automated Cleaning - BMH lifecycle and cleaning modes