Hello all,
I've just started working on the new Yùn, and I find it inspiring.
I wanted to share a neat trick I found for using the microSD card as filesystem expansion.
I got a 8Gb microSD and repartitioned it using a debian VM, so to have one 4 Gb partition formatted as vfat plus one 4Gb partition formatted as ext3. Once mounted on the Yùn, it sees the two partitions as /dev/sda1 (vfat) and /dev/sda2 (ext3).
Then I followed instructions on OpenWRT wiki with slight modifications:
1.
tar -C /overlay -cvf - . | tar -C /mnt/sda2 -xf -
mkdir /mnt/sd
- Added the following lines at the end of /etc/config/fstab:
config mount
option device '/dev/sda1'
option fstype 'vfat'
option enabled '1'
option target '/mnt/sd'config mount
option target /overlay
option device /dev/sda2
option fstype ext3
option options rw,sync
option enabled 1
option enabled_fsck 0
- Reboot.
Now I have 4 Gb of exchange space available on the microSD, readable form Mac or Win PCs, plus other 4 Gb of disk space available to linino for installing additional opkg packages without wasting write-cycles of the embebbed eprom.
If the microSD is not available on boot, linino is booting fine, although, of course, additional packages installed via opkg are not available.
Here's the df output:
root@ArduinoPB:~# df
Filesystem 1K-blocks Used Available Use% Mounted on
rootfs 3724584 18108 3513944 1% /
/dev/root 7168 7168 0 100% /rom
tmpfs 30568 144 30424 0% /tmp
tmpfs 512 0 512 0% /dev
/dev/sda2 3724584 18108 3513944 1% /overlay
overlayfs:/overlay 3724584 18108 3513944 1% /
/dev/sda1 3896164 1016 3895148 0% /mnt/sd
You see that the root filesystem has exactly the same space as /dev/sda2, and it is in fact overlaid by the microSD partition.
Cheers,
-P.