Examples

extroot.txt

@@ -5,35 +5,18 @@ single ext4 partition, no data copied from internal flash.
 
 Assumptions (based on your box):
 
-Device: GL-iNet XE300
-
-OpenWrt: 24.x, fresh flash
-
-SD card location: built-in slot
+Device: GL-iNet XE300, OpenWRT 24.10.4
 
 Detected as: /dev/sda with one partition /dev/sda1
 
-Overlay: You don't care about existing data on the card or in the old overlay
-
 1. Insert card & install required packages
 
-Insert the microSD card.
-SSH into the router (root@192.168.x.x, etc).
-
-Install the extroot-related packages:
-
 opkg update
 opkg install block-mount kmod-fs-ext4 kmod-usb-storage e2fsprogs
 
-
-What they do:
-
 block-mount - block info, fstab handling, extroot logic
-
 kmod-fs-ext4 - kernel driver for ext4 filesystem
-
 kmod-usb-storage -  makes the SD slot show up as /dev/sda
-
 e2fsprogs - provides mkfs.ext4
 
 2. Confirm the SD card is /dev/sda and /dev/sda1
@@ -43,42 +26,25 @@ Check dmesg:
 dmesg | grep -i sd
 
 
-On the XE300 you should see:
-
+Sample Output:
 sd 0:0:0:0: [sda] 1000005632 512-byte logical blocks: (512 GB/477 GiB)
 sda: sda1
 sd 0:0:0:0: [sda] Attached SCSI removable disk
 
 
-This tells you:
-
-Disk: /dev/sda
-
-Partition already present: /dev/sda1
-
-If /dev/sda1 is missing, you'd need to partition manually. In your case, it exists already.
-
 3. Format /dev/sda1 as ext4 for extroot
 mkfs.ext4 -L extroot /dev/sda1
 
-
-If you get a warning like “contains an exfat file system - Proceed anyway? (y,N)”, type:
-
-y
-
-
 You should see output ending with success and a UUID.
 
 4. Grab the UUID and create the extroot fstab entry
 UUID=$(block info | awk -F\" '/sda1/ {print $2}')
 echo $UUID
 
-
 Sample UUID output:
 
 4851f00e-696b-47d3-a529-82c2aca292db
 
-
 Now write the minimal extroot config using uci:
 
 uci set fstab.extroot="mount"
@@ -88,7 +54,6 @@ uci set fstab.extroot.fstype="ext4"
 uci set fstab.extroot.enabled="1"
 uci commit fstab
 
-
 Sanity-check the file:
 
 cat /etc/config/fstab
@@ -111,15 +76,8 @@ config mount 'extroot'
     option enabled '1'
 
 
-Not included:
-
-No /rwm mount
-
-No copy of internal overlay
-
-This is a clean, SD-only overlay setup.
-
 5. Reboot into extroot
+
 reboot
 
 Wait for the router to come back up, then SSH in again.
@@ -140,26 +98,10 @@ overlayfs:/overlay  468.3G  2.1M     444.4G  0% /
 Explanation:
 
 /dev/root at /rom → read-only squashfs from flash
-
 /dev/sda1 at /overlay → SD card is the writable layer
-
 overlayfs:/overlay on / → full rootfs = ROM + SD overlay
-
 You now have a 468 GB OpenWrt box.
 
-Extra checks (optional)
-mount | grep sda1
-mount | grep overlay
-
-
-Should return:
-
-/dev/sda1 on /overlay type ext4
-overlayfs:/overlay on / type overlay
-
-7. Quick functional test
-opkg install tcpdump
-df -h /overlay
-
-
-You should see a small increase in Used for /dev/sda1, proving packages are installed to SD-backed overlay—not internal flash.
+No /rwm mount
+No copy of internal overlay
+This is a clean, SD-only overlay setup.