Move over stuff from nixos-servers

docs/longhorn.md

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+# Longhorn notes
+
+## Migration from NFS to Longhorn
+
+1. Delete the workload, and delete the PVC and PVC using NFS.
+2. Create Longhorn volumes as described below.
+3. Copy NFS data from lewis.dmz to local disk.
+4. Spin up a temporary pod and mount the Longhorn volume(s) in it:
+   ```nix
+    {
+      pods.testje.spec = {
+        containers.testje = {
+          image = "nginx";
+  
+          volumeMounts = [
+            {
+              name = "uploads";
+              mountPath = "/hedgedoc/public/uploads";
+            }
+          ];
+        };
+  
+        volumes = {
+          uploads.persistentVolumeClaim.claimName = "hedgedoc-uploads";
+        };
+      };
+    }
+   ```
+5. Use `kubectl cp` to copy the data from the local disk to the pod.
+6. Delete the temporary pod.
+7. Be sure to set the group ownership of the mount to the correct GID.
+7. Create the workload with updated volume mounts.
+8. Delete the data from local disk.
+
+## Creation of new Longhorn volumes
+
+While it seems handy to use a K8s StorageClass for Longhorn, we do *not* want to use that.
+If you use a StorageClass, a PV and Longhorn volume will be automatically provisioned.
+These will have the name `pvc-<UID of PVC>`, where the UID of the PVC is random.
+This makes it hard to restore a backup to a Longhorn volume with the correct name.
+
+Instead, we want to manually create the Longhorn volumes via the web UI.
+Then, we can create the PV and PVC as usual using our K8s provisioning tool (e.g. Kubectl/Kubenix).
+
+Follow these actions to create a Volume:
+1. Using the Longhorn web UI, create a new Longhorn volume, keeping the following in mind:
+     - The size can be some more than what we expect to reasonable use. We use storage-overprovisioning, so the total size of volumes can exceed real disk size.
+     - The number of replicas should be 2.
+2. Enable the "backup-nfs" recurring job for the Longhorn volume.
+3. Disable the "default" recurring job group for the Longhorn volume.
+4. Create the PV, PVC and workload as usual.
+
+## Disaster recovery using Longhorn backups
+
+Backing up Longhorn volumes is very easy, but restoring them is more tricky.
+We consider here the case when all our machines are wiped, and all we have left is Longhorn backups.
+To restore a backup, perform the following actions:
+1. Restore the latest snapshot in the relevant Longhorn backup, keeping the following in mind:
+   - The name should remain the same (i.e. the one chosen at Longhorn volume creation).
+   - The number of replicas should be 2.
+   - Disable recurring jobs.
+2. Enable the "backup-nfs" recurring job for the Longhorn volume.
+3. Disable the "default" recurring job group for the Longhorn volume.
+4. Create the PV, PVC and workload as usual.
+
+## Recovering Longhorn volumes without a Kubernetes cluster
+
+1. Navigate to the Longhorn backupstore location (`/mnt/longhorn/persistent/longhorn-backup/backupstore/volumes` for us).
+2. Find the directory for the desired volume: `ls **/**`.
+3. Determine the last backup for the volume: `cat volume.cfg | jq '.LastBackupName'`.
+4. Find the blocks and the order that form the volume: `cat backups/<name>.cfg | jq '.Blocks'`.
+5. Extract each block using lz4: `lz4 -d blocks/XX/YY/XXYY.blk block`.
+6. Append the blocks to form the file system: `cat block1 block2 block3 > volume.img`
+7. Lastly we need to fix the size of the image. We can simply append zero's to the end until the file is long enough so `fsck.ext4` does not complain anymore.
+8. Mount the image: `mount -o loop volume.img /mnt/volume`.

docs/media.md

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+# Media
+
+[profilarr](https://github.com/Dictionarry-Hub/profilarr) was used to import the "1080p Transparent" quality profile to both Radarr and Sonarr.
+Profilarr has some neat tools that magically applies custom formats and quality definitions.
+As far as I understand, these are used to indentify files that are high quality.
+Profilarr can then also import a quality profile, which uses the aforementioned definitions to select torrents in my desired format.
+In my case, I have chosen "1080p Transparent."
+According to the [docs](https://selectarr.pages.dev/):
+> Projected Size: 10 - 15gb
+>
+> Description: Prioritizes 1080p transparent releases. Lossy audio is allowed, and all upgrades are allowed. HDR is banned.