I have an OpenWrt-based system on an embedded device.
Rootfs is mounted as overlayfs
# mount
mtd:ubi_rootfs on /rom type squashfs (ro,relatime)
overlayfs:/overlay on / type overlay (rw,noatime,lowerdir=/,upperdir=/overlay/upper,workdir=/overlay/work)
...
There is a number of changed files:
# find /overlay/upper/ -type f
/overlay/upper/etc/passwd
/overlay/upper/etc/sysstat/sysstat
/overlay/upper/etc/bluetooth/csr8x11-mac.psr
/overlay/upper/etc/shadow
/overlay/upper/etc/ethers
...
I need to revert them