Hi All,
Another question. 
I have D Link DIR-600 (HW B2).
It was first flashed with openwrt-19.07.0-ramips-rt305x-dir-600-b1-squashfs-factory.bin and then after openwrt-19.07.0-ramips-rt305x-dir-600-b1-squashfs-sysupgrade.bin.
Everything works as expected until I reboot the router. For any reason if I reboot, all the settings are lost. And I must do everything from scratch.
Doubting on memory issue, I did check the memory. And there I don't see any issue...
root@OpenWrt:~# df -h
Filesystem Size Used Available Use% Mounted on
/dev/root 3.0M 3.0M 0 100% /rom
tmpfs 13.8M 280.0K 13.5M 2% /tmp
tmpfs 13.8M 60.0K 13.7M 0% /tmp/root
overlayfs:/tmp/root 13.8M 60.0K 13.7M 0% /
tmpfs 512.0K 0 512.0K 0% /dev
However, I do see that it uses temporary overlay area as it is not able to mount it.
root@OpenWrt:~# logread | grep jffs2
Mon Jan 6 16:47:23 2020 kern.notice kernel: [ 0.000000] Kernel command line: console=ttyS0,57600 rootfstype=squashfs,jffs2
Mon Jan 6 16:47:23 2020 kern.info kernel: [ 0.510900] jffs2: version 2.2 (NAND) (SUMMARY) (LZMA) (RTIME) (CMODE_PRIORITY) (c) 2001-2006 Red Hat, Inc.
Mon Jan 6 16:47:23 2020 user.notice kernel: [ 12.527850] mount_root: jffs2 not ready yet, using temporary tmpfs overlay
Mon Jan 6 16:49:03 2020 kern.err kernel: [ 130.776285] jffs2: Too few erase blocks (4)
**Mon Jan 6 16:49:03 2020 daemon.err mount_root: failed - mount -t jffs2 /dev/mtdblock6 /rom/overlay: Not a tty**
root@OpenWrt:~# logread | grep -i overlay
Mon Jan 6 16:47:23 2020 user.notice kernel: [ 12.527850] mount_root: jffs2 not ready yet, **using temporary tmpfs overlay**
**Mon Jan 6 16:49:03 2020 daemon.err mount_root: failed - mount -t jffs2 /dev/mtdblock6 /rom/overlay: Not a tty**
root@OpenWrt:~#
Can you see why it is not able to mount overlay...
Thanks again !!!