add fstab docs

system/fstab.md

@@ -0,0 +1,40 @@
+---
+title: "fstab"
+tags: [ "Documentation", "System" ]
+---
+# Basics
+
+The ordering of `/etc/fstab` is
+
+1. disk
+2. mount point
+3. filesystem type
+4. options
+5. dump
+6. pass
+
+E.g.:
+
+```
+UUID=877f14e8-4738-46b0-884f-ba330dad1a7d       /mnt/biggie                     ext4        nofail,rw,relatime      0 2
+
+UUID=B21648C416488AF5 /mnt/share ntfs       nofail,rw,nosuid,nodev,user_id=0,group_id=0,allow_other,blksize=4096 0 0
+```
+
+## 5: Dump
+
+Ignore this obsolete option.
+
+## 6: Pass
+
+| Number | Meaning               |
+|        |                       |
+|   0    | Swap (or not mounted) |
+|   1    | Mount at /            |
+|   2    | Mount somewhere else  |
+
+## Options
+
+- `nofail` means the computer will not fail to boot, even if the drive fails, or is unplugged. It's a good option for everything except `/`.
+- noauto means 'don't mount on boot' (but you can still mount with `mount -a`).
+