Filesystem Setup

mkfs / mount / fstab commands for writable Forest OS installs. Copy-pasteable.

See Choosing a Filesystem for which filesystem to pick: FAT is writable (fat.c, Production), ext2 is read-only (ext2.c). Rule: want persistence → FAT root.

Replace /dev/sdX1, /dev/sdX2, /dev/sda1 with your real partition (check with blkid first). All mkfs commands erase the target.

1. Format Partitions with mkfs

FAT32 root (writable install)

mkfs -t fat32 -L ROOT /dev/sda1

FAT32 ESP (UEFI boot partition)

mkfs -t fat32 -L ESP /dev/sda1

FAT32 data partition (separate /home or /data)

mkfs -t fat32 -L FOREST-DATA /dev/sda2

ext2 root (read-only system image)

mkfs -t ext2 /dev/sda1

Verify the format and label after each mkfs:

blkid /dev/sda1
blkid /dev/sda2

Expected output shows type and label, e.g. LABEL="ROOT" TYPE="vfat" or LABEL="ESP" TYPE="vfat" / TYPE="ext2".

Check / repair before first mount:

fsck /dev/sda1
fsck /dev/sda2

2. Mount

Create mount points and mount by hand:

mkdir -p /mnt/root /mnt/data
mount -t vfat /dev/sda1 /mnt/root
mount -t vfat /dev/sda2 /mnt/data

Mount an ext2 image (read-only driver — writes will fail):

mkdir -p /mnt/ext2
mount -t ext2 /dev/sda1 /mnt/ext2

Mount everything listed in /etc/fstab at once (after editing fstab):

mount -a

Bind-mount (mirror one directory tree at a second path, e.g. for installer chroots):

mkdir -p /mnt/root/home
mount --bind /mnt/data /mnt/root/home

Mount an ISO / disk image via loop (no USB burn needed):

mkdir -p /mnt/iso
mount -o loop /root/forest-live.iso /mnt/iso

Confirm mounts and space usage:

df -h
du -sh /mnt/root /mnt/data
blkid

3. fstab Variants

Edit /etc/fstab on the installed root. One line per filesystem: <device> <mountpoint> <type> <options> <dump> <pass>. After editing, run mount -a to apply, then df -h to confirm.

Variant A — FAT root (recommended writable install)

Root + tmpfs + procfs/sysfs. Everything persists because the root driver is writable.

/dev/sda1  /      vfat   defaults  0 0
tmpfs      /tmp   tmpfs  defaults  0 0
proc       /proc  procfs defaults  0 0
sys        /sys   sysfs  defaults  0 0

mount -a
df -h

Variant B — ext2 root + FAT /home (sealed system, writable home)

System files live on a read-only ext2 root; user data lives on a writable FAT partition. Edits under / cannot be saved — save work under /home.

/dev/sda1  /      ext2   ro        0 0
/dev/sda2  /home  vfat   defaults  0 0
tmpfs      /tmp   tmpfs  defaults  0 0
proc       /proc  procfs defaults  0 0
sys        /sys   sysfs  defaults  0 0

mount -a
df -h
touch /home/test-write && echo "home writable: OK" && rm /home/test-write

Copy-to-writable workflow for files on the read-only root:

cp /README.txt /home/

Variant C — Persistent USB (live system + writable data)

Live boot media stays untouched; a labeled FOREST-DATA partition holds changes, configs, and packages across reboots.

/dev/sda1  /            vfat   ro        0 0
/dev/sda2  /data        vfat   defaults  0 0
tmpfs      /tmp         tmpfs  defaults  0 0
proc       /proc        procfs defaults  0 0
sys        /sys         sysfs  defaults  0 0

With a bind-mount so /home lands on the persistent partition:

/dev/sda1  /            vfat   ro        0 0
/dev/sda2  /data        vfat   defaults  0 0
/data/home /home        none   bind      0 0
tmpfs      /tmp         tmpfs  defaults  0 0
proc       /proc        procfs defaults  0 0
sys        /sys         sysfs  defaults  0 0

mkdir -p /data /data/home /home
mount -a
df -h
touch /data/test-write && echo "persistence writable: OK" && rm /data/test-write

4. Verify: blkid / fsck / df / du

Run after mkfs, after editing fstab, and after mount -a:

blkid
fsck /dev/sda1
fsck /dev/sda2
df -h
du -sh / /home /data /tmp

Command	Checks
`blkid`	Partition exists, type (`vfat`/`ext2`), label (`ROOT`/`ESP`/`FOREST-DATA`) matches your `fstab` device
`fsck /dev/sda1`	Filesystem clean before mounting (run while unmounted)
`df -h`	Every `fstab` entry actually mounted, free space sane
`du -sh / /home /data`	Data lands where you expect (root vs `/home` vs `/data`)

5. Read-Only Mount Test and Remount rw

Test that a mount is truly read-only, then remount it writable (FAT only — ext2 stays read-only under the kernel driver):

mkdir -p /mnt/test
mount -r -t vfat /dev/sda1 /mnt/test
touch /mnt/test/should-fail && echo "UNEXPECTED: wrote to read-only mount" || echo "OK: read-only mount blocks writes"

Remount the same mount point read-write without unmounting:

mount -o remount,rw /mnt/test
touch /mnt/test/write-ok && echo "OK: remount rw works" && rm /mnt/test/write-ok

Same test directly on the live root or data mount:

mount -r -o remount /data
touch /data/should-fail && echo "UNEXPECTED: wrote to read-only mount" || echo "OK: /data is read-only"
mount -o remount,rw /data
touch /data/write-ok && echo "OK: /data writable again" && rm /data/write-ok

ext2 note: mount -o remount,rw on an ext2 mount will not make it writable — ext2.c is read-only. If the write test keeps failing on ext2, that is expected; keep a FAT /home or /data (Variant B/C) for anything you need to save.