Asus-Merlin JFFS wear?

[Lynx]

On the helpful wiki it is stated in https://github.com/RMerl/asuswrt-merlin.ng/wiki/JFFS:

Starting with 378.50, this option is enabled by default. If for some reason you need to erase its content, you can do so from the Administration page, under the System tab. Formatting the JFFS partition requires a reboot to take effect. Note that formatting it might possibly require a second reboot afterwards, if it fails to properly mount after that first reboot.

I do not recommend doing frequent writes to this area, as it will prematurely wear out the flash chip. This is a good place to put files that are written once like scripts or kernel modules, or that rarely get written to. Do not put files that get constantly written to (such as high activity logfiles) - store these on a USB disk instead. Replacing a worn out USB flash disk is much cheaper than replacing the whole router if flash sectors get worn out - they have a limited number of write cycles.

Given the above, why is JFFS enabled by default if its use results in wear and in particular why is syslog being copied to JFFS by default?

ls -alh /jffs/

-rw-rw-rw- 1 admin root 24.2K Jul 9 09:44 syslog.log
-rw-rw-rw- 1 admin root 256.1K Jul 9 09:44 syslog.log-1

Update: it looks from another thread like this may be something that ASUS itself added. Perhaps worrying about this is akin to worrying about router temperatures. And perhaps a fix to stop it might be compared with sticking a fan onto the router using 3D printing or otherwise. As in, life it too short.

 

[ColinTaylor]

That information is out of date (version 378.50!) and applied to the NVRAM chips used in very old models. Merlin has stated many times since that jffs wear is not a problem any more (unless you're really hammering that partition). All writes to jffs are compressed and cached in memory so the actual amount of physical writing is minimised.