"Your router is running low on free NVRAM" after FW upgrade

[ZoloN]

hi all (specially @RMerlin )

after FW upgrade from 384.19_0 to 386.2_2 I got this nasty message.
my question is: is it possible to compress somehow the content of the NVRAM? or do I really need to do factory reset? my setup is quite complex (includes site2site OpenVPN tunnel, MESH setup, etc...)
I have found records in custom_clientlist for devices which aren't on my network anymore for a long-long time (several months)

 

[ZoloN]

found useful answer here:

for line in `nvram show | grep ^[^=]*=$ `; do var=${line%*=}; nvram unset $var; done; nvram commit

please note: there are some other commands, which tries to delete anything ending with "=" charcter, assuming that this is an empty variable. unfortunately, there are some variables containing Base64 content (e.g. passwords) and they end with "=" character too!!!