added zfs notes

content/guides/http-status-codes.md

@@ -1,5 +1,4 @@
 ---
-status: new
 description: A comical explanation of various HTTP status codes.
 ---
 

content/guides/zfs-notes.md

@@ -0,0 +1,104 @@
+---
+status: new
+description: Various notes about my usage of ZFS/OpenZFS.
+---
+
+# ZFS Notes
+
+In this document, replace `worldsgrave` with the name of your zpool.
+
+## Recommended settings
+
+### Compression
+
+Use `lz4` compression, it's fast and efficient.
+
+```shell
+zfs set compression=lz4 worldsgrave
+```
+
+### Access Time
+
+Turn off `atime`, it's useless.
+
+```shell
+zfs set atime=off worldsgrave
+```
+
+### De-Duplication
+
+!!! warning "De-Duplication"
+    **NEVER** use de-dupe, it's a massive performance hit.
+
+## Scheduled Scrubing
+
+Create the following files:
+
+??? example "/etc/systemd/system/zfs-scrub@.service"
+
+    ``` desktop
+    [Unit]
+    Description=zpool scrub on %i
+
+    [Service]
+    Nice=19
+    IOSchedulingClass=idle
+    KillSignal=SIGINT
+    ExecStart=/usr/sbin/zpool scrub %i
+
+    [Install]
+    WantedBy=multi-user.target
+    ```
+
+??? example "/etc/systemd/system/zfs-scrub@.timer"
+
+    ``` desktop
+    [Unit]
+    Description=Monthly zpool scrub on %i
+
+    [Timer]
+    OnCalendar=monthly
+    AccuracySec=1h
+    Persistent=true
+
+    [Install]
+    WantedBy=multi-user.target
+    ```
+
+Enable and start the new service:
+
+```shell
+systemctl daemon-reload
+systemctl enable zfs-scrub@worldsgrave.timer
+```
+
+## Scheduled Snapshots
+
+Install zrepl, see [zrepl.yaml](zrepl.yaml) for reference.
+
+## Useful Commands
+
+### List datasets
+
+```shell
+zfs list -o type,name,available,used,logicalused,usedbysnapshots,compressratio,mountpoint
+```
+
+### List snapshots
+
+```shell
+zfs list -t snapshot
+```
+
+### Recordsize
+
+```shell
+ zfs get recordsize -t filesystem
+```
+
+### Aliases
+
+``` shell
+alias zls="zfs list -o type,name,available,used,logicalused,usedbysnapshots,compressratio,mountpoint"+
+alias zsl="zfs list -t snapshot"
+```

content/guides/zfs-notes/zrepl.yaml

@@ -0,0 +1,99 @@
+global:
+  logging:
+    # use syslog instead of stdout because it makes journald happy
+    - type: syslog
+      format: human
+      level: warn
+  monitoring:
+    # Maker prometheus metrics available for scraping
+    - type: prometheus
+      listen: ":9811"
+      listen_freebind: true # Enabled, so that zrepl will listen on all IPs, even if they are bound after zrepl starts
+
+# see /usr/share/doc/zrepl/examples
+# or https://zrepl.github.io/configuration/overview.html
+# or https://zrepl.github.io/quickstart/backup_to_external_disk.html
+
+jobs:
+  # snapshot creation + pruning for worldsgrave
+  - name: worldsgrave_snapshots
+    type: snap
+    filesystems: {
+        "worldsgrave<": true,
+        "worldsgrave/zrepl<": false, # Don't snapshot snapshots from rpool, that would be super dumb
+        "worldsgrave/k8s<": false, # Dont' snapshot k8s PVs, the ZFS operator will do that as needed
+        "worldsgrave/timemachine<": false, # Don't snapshot timemachine backups, that would also be dumb
+      }
+    # create snapshots with prefix `zrepl_` every 15 minutes
+    snapshotting:
+      type: periodic
+      interval: 15m
+      prefix: zrepl_
+    pruning:
+      keep:
+        # Fade-out scheme for snapshots starting with `zrepl_`
+        # - Keep all created in the last hour
+        # - Keep 24 each 1 hour apart
+        # - Keep 14 each 1 day apart
+        # - All older snapshots will be destroyed unless other keep rules apply to them
+        - type: grid
+          grid: 1x1h(keep=all) | 24x1h | 14x1d
+          regex: "^zrepl_.*"
+        # Keep all snapshots that don't have the `zrepl_` prefix
+        # This protects manually created snapshots from being pruned by zrepl
+        - type: regex
+          negate: true
+          regex: "^zrepl_.*"
+
+  # Provide a destination on worldsgrave for snapshots from rpool
+  - name: "worldsgrave_sink"
+    type: sink
+    root_fs: "worldsgrave/zrepl"
+    serve:
+      type: local
+      listener_name: localsink
+
+  # Backup root snapshots to worldsgrave
+  - name: "backup_root"
+    type: push
+    connect:
+      type: local
+      listener_name: localsink
+      client_identity: backup_root
+    filesystems: {
+        "rpool<": true,
+        "rpool/k3s_agent<": false, # Don't snapshot the k3s agent zvol, it's not needed
+        "rpool/k8s<": false, # Dont' snapshot k8s PVs, the ZFS operator will do that as needed
+      }
+    # Create snapshots with prefix `zrepl_` every 30 minutes
+    snapshotting:
+      type: periodic
+      interval: 30m
+      prefix: zrepl_
+    pruning:
+      keep_sender:
+        # Keep any snapshots on rpool that haven't been replicated to worldsgrave/zrepl yet
+        - type: not_replicated
+        # Fade-out scheme for snapshots starting with `zrepl_` on rpool
+        # - Keep all created in the last hour
+        # - Keep 24 each 1 hour apart
+        # - All older snapshots will be destroyed unless other keep rules apply to them
+        - type: grid
+          grid: 1x1h(keep=all) | 24x1h
+          regex: "zrepl_.*"
+        # Keep all snapshots that don't have the `zrepl_` prefix
+        - type: regex
+          negate: true
+          regex: "^zrepl_.*"
+      keep_receiver:
+        # Fade-out scheme for snapshots starting with `zrepl_` on worldsgrave/zrepl
+        # - Keep 14 each 1 day apart
+        # - All older snapshots will be destroyed unless other keep rules apply to them
+        - type: grid
+          grid: 14x1d
+          regex: "zrepl_.*"
+        # Keep all snapshots that don't have the `zrepl_` prefix
+        # This protects manually created snapshots from being pruned by zrepl
+        - type: regex
+          negate: true
+          regex: "^zrepl_.*"

mkdocs.yml

@@ -9,6 +9,7 @@ nav:
       - guides/rpi-k8s-talos-terraform.md
       - guides/mkdocs-material-insider-github-pages-action.md
       - guides/http-status-codes.md
+      - guides/zfs-notes.md
   - Smart Home:
       - smart-home/architecture.md
       - smart-home/garage-door.md