Root home folder wiped

I have noticed the root home folder in the gl-inet ar300m gets wiped each time I upgrade the firmware of the router. Is there a directory I should be moving my files before upgrade so that I can keep them? The rest of the configuration in router is actually kept: firewall rules, crontab, etc

BusyBox v1.25.1

Reboot (17.01.4, r3560-79f57e422d)

root@GL-AR300M:~# uname -a
Linux GL-AR300M 4.4.92 #0 Tue Oct 17 17:46:20 2017 mips GNU/Linux

root folder is not retained.

change the /lib/upgrade/keep.d folder and add your /root in one of the files

excellent. thanks for the prompt reply