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Overview

Rescue mode boots an instance from a temporary rescue image while preserving the original root disk as a secondary device. This allows you to diagnose and repair boot failures, corrupted filesystems, or locked-out SSH configurations without destroying the instance.
Prerequisites
  • An instance in Active or Shutoff status
  • The instance must not be locked
  • CLI access required — the Rescue action is not available in the Dashboard GUI
The Rescue and Unrescue actions are CLI-only operations. They are not available in the Polystack Dashboard. Use the CLI commands below to enter and exit rescue mode.

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Enter Rescue Mode

1

Authenticate

Load credentials
2

Rescue the instance

Enter rescue mode (default rescue image)
Rescue with a specific image
The instance reboots into rescue mode. The original root disk is attached as a secondary device (typically /dev/vdb).
3

Connect and repair

SSH into the instance using the rescue image credentials. Mount the original root disk and perform repairs:
Mount the original root disk
Example: fix SSH config

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Exit Rescue Mode

Unrescue the instance
The instance reboots from its original root disk with the repairs applied.
Instance returns to Active status on its original root disk.

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Next Steps

Instance Snapshots

Create a snapshot before rescue as a safety measure

Reboot an Instance

Try a reboot before rescue for less severe issues

Console Access

Use the VNC console for out-of-band diagnostics

Troubleshooting

Resolve boot failures and rescue mode issues