Init bakke (!87)

New backup server just dropped!
This server is awfully slow, and the mdraid setup is awfully slow, and I doubt that this will be a good experience, but we now have a backup server again?

- Tried Disko and nixos-anywhere
- Tried using mdraid
- Found that md is ancient and bad
- Found that disko is 100% extra steps, and a lot more complicated and noisy than just formatting your disks yourself
- Found that systemd-boot doesn't support mdraid
- Found that we probably don't need to mirror the boot partition :)
- Found that old hardware is slow
- Found that old hardware can have poor support for iPXE with UEFI, and might do weird BIOS stuff on you when you least expect it
- Reaffirmed that zfs is love

Current disk layout:
- mdraid for boot/root disk
    - 4TB WD Red with 500MiB ESP with systemd-boot, Remaining mdraid - Old?
    - 4TB WD Red with 500MiB Unused partition, Remaining mdraid - Old?
- zfs pool "tank" for the actual backup data
    - 8TB Toshiba MG08 - New
    - 8TB Exos 7E10 - New

TODO:

- Document the death of Toriel on the wiki
- Document Bakke on the wiki
  - ... describing the poco loco disk layout
- Start backing stuff up
  - Restic? Borg? Rsync?
  - Make backup retention policy and zfs snapshot system
  - Document backup procedures

Reviewed-on: https://git.pvv.ntnu.no/Drift/pvv-nixos-config/pulls/87
Co-authored-by: Felix Albrigtsen <felix@albrigtsen.it>
Co-committed-by: Felix Albrigtsen <felix@albrigtsen.it>

hosts/bakke/disks.nix

@@ -0,0 +1,83 @@
+{
+  # https://github.com/nix-community/disko/blob/master/example/boot-raid1.nix
+  # Note: Disko was used to create the initial md raid, but is no longer in active use on this host.
+  disko.devices = {
+    disk = {
+      one = {
+        type = "disk";
+        device = "/dev/disk/by-id/ata-WDC_WD40EFRX-68WT0N0_WD-WCC4E2EER6N6";
+        content = {
+          type = "gpt";
+          partitions = {
+            ESP = {
+              size = "500M";
+              type = "EF00";
+              content = {
+                type = "mdraid";
+                name = "boot";
+              };
+            };
+            mdadm = {
+              size = "100%";
+              content = {
+                type = "mdraid";
+                name = "raid1";
+              };
+            };
+          };
+        };
+      };
+      two = {
+        type = "disk";
+        device = "/dev/disk/by-id/ata-WDC_WD40EFRX-68WT0N0_WD-WCC4E7LPLU71";
+        content = {
+          type = "gpt";
+          partitions = {
+            ESP = {
+              size = "500M";
+              type = "EF00";
+              content = {
+                type = "mdraid";
+                name = "boot";
+              };
+            };
+            mdadm = {
+              size = "100%";
+              content = {
+                type = "mdraid";
+                name = "raid1";
+              };
+            };
+          };
+        };
+      };
+    };
+    mdadm = {
+      boot = {
+        type = "mdadm";
+        level = 1;
+        metadata = "1.0";
+        content = {
+          type = "filesystem";
+          format = "vfat";
+          mountpoint = "/boot";
+        };
+      };
+      raid1 = {
+        type = "mdadm";
+        level = 1;
+        content = {
+          type = "gpt";
+          partitions.primary = {
+            size = "100%";
+            content = {
+              type = "filesystem";
+              format = "ext4";
+              mountpoint = "/";
+            };
+          };
+        };
+      };
+    };
+  };
+}