Asus routers and NVRAM (AC-RT3200)

[Nigel Jones]

Today my primary ISP failed... after a few hours on a tethered phone I spent a moment setting up dual WAN as my old ISP is still active for a couple of weeks. Worked a treat.

Having done this I noticed my nvram was getting low (I'm running merlin firmware). Currently at 62971 / 65536 bytes

Currently I have enabled
- AIprotection (all options, looks useful)
- Adaptive QOS including app analysis, web history
- traffic stats
- 2 OpenVPN servers (1 tap, 1 tun) - just about 2 ids on each
- dual WAN

I'm not using an NFS, SNB, other USB devices etc.

I was a little surprised that I don't see I'm really using the device much more than intended yet hitting this rather low limit.

Are there particular features above that are likely to eat more nvram?
Am I right in thinking that the first (cheapest) ASUS model that "fixes" this is the AC-88u? (and then the 5300)? But not any revisions of the AC-68u nor the weird AC-87u ?
Does the firmware do any automatic garbage collection? So having it pretty full isn't really an issue?

 

[RMerlin]

The RT-AC3200 is a specific case. Same problem as with the RT-N16, they added features to these two devices without also increasing nvram, which leads to running out of nvram rather easily, even with a fairly basic setup.

The RT-AC68U does not have such issue because it only has two wireless radios - most of that space is used by the AC3200's third radio.

 

[Nigel Jones]

Thanks, yes I can see that radio is definitely taking up quite a bit more config data.

Interesting the vpn config is quite significant too
nigel@RT-AC3200-AD90:/tmp/home/root# nvram show | grep '^vpn' | wc
size: 60947 bytes (4589 left)
381 381 8696


In particular there are variables present (I cleared them, they came back) that relate to all the clients/servers, even if, as in my case, I'm only using one vpn server and no clients. Any scope for removing anything there?

 

[RMerlin]

Any scope for removing anything there?

Default variables cannot really be removed, they will eventually just be re-created.

I did the test, and each OpenVPN client instance takes close to 1 KB of nvram.

 

[DiGriz]

So what would be the best way to lower the NVRAM use? Can traffic.db be moved to USB? Or something along those lines?