more journalctl checks

system/systemd/journal.md

@@ -2,6 +2,20 @@
 title: "journal"
 tags: [ "Documentation", "systemd" ]
 ---
+
+See a running log of all system messages:
+
+
+```bash
+journalctl -f
+```
+
+Or just one unit (`sshd`):
+
+```bash
+journalctl -f -u sshd
+```
+
 Find errors since November
 
 ```bash
@@ -14,3 +28,11 @@ Limit size to 2G.
 journalctl --vacuum-size=2G
 ```
 
+Log the fact that you've installed your own `dnsmasq` on your system to `journalctl`, so that you can notice why your system's broken:
+
+
+```bash
+logger "Installed new dnsmasq"
+sudo journalctl -f
+```
+