Unraid

Unraid keeps its whole setup on its boot device: array and pool layout, shares, users, network, Docker templates, plugins, VM settings and the license key. Backuparr backs that up with Unraid’s own Boot Device Backup (on Main, click the boot device, then Boot Device Backup), the zip you’d download by hand. It works the same on a USB flash drive and on internal boot (Unraid 7.3 and later), and was tested on Unraid 7.3.5 and 7.4.0.

The zip is kept as Unraid makes it: everything on the boot device except the previous Unraid release Unraid keeps for downgrades, so about 1.2 GB with Unraid’s own files. That’s what lets the USB Flash Creator restore it in one step; a zip of only the config folder doesn’t boot. It holds the license, the root and share password hashes, SSH keys and WireGuard keys - more than Unraid Connect’s flash backup, which leaves passwords and keys out - so it’s always encrypted. Array data, appdata and VMs aren’t on the boot device and aren’t in it.

Unraid’s guides: Backing up the boot device and Changing the boot device.

Setting it up

Unraid’s web UI has only the root user, and neither its API nor a mounted folder offers the boot device to anything else (the boot device can be read only by root), so the card takes the root password. It’s encrypted at rest, and Backuparr uses it only to sign in to the web UI, make the backup and sign out.

On Backuparr’s Unraid card, enter the URL of Unraid’s web UI - the address you open it at, for example http://192.168.1.10 - and the root password, then Test connection. Backuparr can run on the Unraid server itself or anywhere that reaches its web UI. If Unraid redirects to another address (for example a myunraid.net one), enter that address instead.

Unraid ignores sign-ins from an address for 15 minutes after 3 wrong passwords. Backuparr signs in once per backup and never retries, and says so when it’s refused.

Up to Unraid 7.3, Unraid makes the zip on the server before it’s downloaded, and needs free space for it - about 1.5 times what the boot device uses - in memory or on a share such as system. With the array stopped and little memory free, that fails, as Unraid’s own button does; Backuparr says so. From 7.4 the zip is streamed and needs no space on the server.

Backuparr itself needs room for the zip and its encrypted copy while a backup runs - about 2.5 GB in its container’s temporary folder - and each kept backup takes about 1.2 GB at every destination, so pick the retention with that in mind.

The certificate

With Use SSL/TLS set to Yes (Settings > Management Access), Unraid serves its web UI with a self-signed certificate. The first Test connection shows it (name and expiry, and the SHA-256 fingerprint on the ? next to SHA-256): click Trust and Save. It works as for OPNsense: a changed certificate stops backups until you trust the new one. A myunraid.net certificate is from a trusted CA and needs nothing.

Restoring

Pick Unraid and a backup on Backuparr’s Restore tab: it shows a Download button (the backup comes back decrypted, as a .zip) and these steps.

A new or replacement drive:

  1. Download the backup.
  2. In the Unraid USB Flash Creator, choose Use custom, pick the downloaded .zip and write it to the USB flash drive.
  3. Boot the server from it. On a new drive, move the license to it with Tools > Registration > Replace Key - see Unraid’s Changing the boot device for the limits.
  4. Check the disk assignments on Main before starting the array.

A backup made while the array was running restores as an array that wasn’t stopped cleanly: Main says “Unclean shutdown detected”, and Unraid checks parity when the array starts, as after a power cut.

Internal boot: restore the backup to a USB flash drive as above and boot from it, then switch to internal boot again (Tools > Internal Boot). Unraid copies the restored setup to the internal drive. Unraid’s Internal Boot FAQ describes the same.

Single files: open the .zip and copy what you need from its config folder back to the same place on the boot device (the flash share, or /boot/config), then reboot.

The download is decrypted and holds the server’s passwords and keys: delete it once Unraid is back.