Bare-metal and VM recovery

File restores cover most requests. When a whole machine is lost (a dead disk, new hardware, a ransomware wipe), restore a disk image from a recovery USB, or rebuild a Proxmox host and restore its guests.

Prepare before a disaster

1. Take disk-image backups of the machines you would need to rebuild: Back up system now in the Windows desktop app, or cvn-agent image-backup on Windows or Linux. Check that they appear in Time Machine as a Disk image.
2. Record each device's backup passphrase in your password manager.
3. Keep a copy of each device's agent.json off the machine. It holds the device token and server address, so treat it like a password.

Make a recovery USB

1. In the user portal, open Time Machine, select the device and choose Download Recovery USB Creator. The download is a small Windows program that carries that device's settings.
2. Run it on any Windows PC and choose a USB stick. It only lists removable USB drives, so it cannot overwrite a system disk.
3. The creator downloads the recovery image from your server, writes it to the stick and adds the device's agent.json.

The recovery USB boots on both BIOS and UEFI machines. You may need to turn off Secure Boot to start it, and turn it back on after the restore.

Restore a disk image

1. Connect the machine to a network with DHCP that can reach your server.
2. Boot it from the recovery USB. The recovery console starts by itself, loads drivers and brings up the network.
3. Enter the backup passphrase when asked. The passphrase is typed only on that machine.
4. Pick a system image restore point.
5. Choose the target disk and confirm. The disk is erased and overwritten. It must be at least as large as the disk that was imaged; the tool refuses a smaller one.
6. When it finishes, reboot and remove the USB.

If the console exits, it leaves you at a shell, where you can retry or investigate.

The recovery tools pull the encrypted image from storage, decrypt it on the machine and write it to the disk block by block.

Notes

• An image of a running Windows system is crash-consistent: Windows recovers it on first boot as if the power had been cut. For a fully consistent image, boot the recovery USB and run cvn-agent image-backup --device <disk> with nothing mounted.
• A restored Windows image boots best on the same or similar hardware.
• To get files out of an image without a bare-metal restore, write it to a file: Save image to file in the Windows desktop app, or cvn-agent image-restore --snapshot <id> --out system.img. Mount the file or attach it to a VM.

Rebuild a Proxmox host

Proxmox guest backups restore onto any compatible Proxmox host.

1. Install Proxmox VE on the new hardware.

2. Install the Linux agent and put the original host's agent.json in /etc/cvn-agent/, so the agent signs in as the old host and can read its restore points.

3. Set CVN_PASSPHRASE to the original passphrase for the commands below.

4. List the guest restore points:

   cvn-agent snapshots --config /etc/cvn-agent/agent.json --json
   

5. Restore each guest onto storage that exists on the new host:

   cvn-agent pve-restore --config /etc/cvn-agent/agent.json --snapshot <id> --vmid <id> --storage <storage>
   

See Proxmox VE for the other options.