'Router running low on free NVRAM' yellow alert notice

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Alystair

New Around Here
I'm getting the blinking 'router is running low on free NVRAM' light on my AC68U. There are 10 reserved DHCP addresses and a second AiMesh device. Below are the usage details to aid /w diagnostic. Is it OK to ignore the blinking light?

Firmware: 386.1
NVRAM usage 62650 / 65536 bytes

Code:
size: 62581 bytes (2955 left)
931 nc_setting_conf
764 custom_clientlist
546 rc_support
339 dhcp_staticlist
315 dhcp_hostnames
306 qos_rulelist
182 fb_comment
166 subnet_rulelist
151 asus_device_list
131 wl1_chansps
129 wps_env_buf
123 fb_browserInfo
112 vlan_rulelist
112 cfg_relist
100 cfg_device_list
92 1:pa5ga2
92 1:pa5ga1
92 1:pa5ga0
77 vpn_serverx_clientlist
72 bwdpi_app_rulelist
 

bbunge

Part of the Furniture
If you upgraded to 386.1 without doing a factory reset you may want to consider doing so. Also check that the /jffs is mounted. I upgraded an AC68U from Asus 3.0.0.4.386.41634, did a factory reset and gained a bit of NVRAM. Do not use saved settings but configure the router manually.
 

Alystair

New Around Here
If you upgraded to 386.1 without doing a factory reset you may want to consider doing so. Also check that the /jffs is mounted. I upgraded an AC68U from Asus 3.0.0.4.386.41634, did a factory reset and gained a bit of NVRAM. Do not use saved settings but configure the router manually.

JFFS is mounted, factory reset would be a bit annoying as I'd need to re-add the second AiMesh device
 

Diamond67

Senior Member
I am not getting any alerts yet, but the NVRAM usage seems to be a bit higher right after updating to 386.1.

Just before updating (while still running fw 384.19) I had
NVRAM usage 57412 / 65536 bytes.

Now with 386.1 I have
NVRAM usage 61170 / 65536 bytes.

Code:
nvram show | awk '{print length(), $0 | "sort -n -r"}' | cut -d"=" -f 1 | head -n 20

gives me the Top 20:

Code:
size: 61101 bytes (4435 left)
931 nc_setting_conf
546 rc_support
485 custom_clientlist
470 dhcp_hostnames
461 dhcp_staticlist
266 acc_list
205 wl1_chansps
166 subnet_rulelist
159 dnspriv_rulelist
135 dms_dir_x
120 qos_rulelist
112 vlan_rulelist
110 vpn_client1_cust2
109 vpn_client_cust2
94 vpn_client1_clientlist
93 vpn_client_clientlist
92 1:pa5ga2
92 1:pa5ga1
92 1:pa5ga0
83 asus_device_list
 

L&LD

Part of the Furniture

ColinTaylor

Part of the Furniture

GoNz0

Very Senior Member
I run this command to free up nvram

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

AppleBag

Regular Contributor
I just came to the forum to post about this, and found his thread. It's happening to me as well, but seems I have plenty of free NVRAM? Whenever I manually empty some big vars in tehe past I've been left with even more than this used amount, but no warning notice.

1612311012553.png


1612311024444.png


I really don't want to do yet another factory reset + hand enter *everything* again. I've done that like 5x in the past already and it gets frustrating having to do it all over again for each new firmware release.
 

Gertjuuh

New Around Here
Same here. Did the update to 386.1. NVRAM used 62724/65536 bytes. Removed a view client names from the DHCP list and the Mac filter list. Still the yellow alert. A read some suggestions but no one tells for sure a succesful solution. Maybe Merlin can help?
 

RMerlin

Asuswrt-Merlin dev
Take it for what is - a warning. You just need to make sure it doesn't ever get completely filled up.
 

OutsideTech

New Around Here
Take it for what is - a warning. You just need to make sure it doesn't ever get completely filled up.
Thank you, good to know that it is what it is, a warning. Very impressed to get such life out of an older router, these updates have been rock solid.
 

Igor

Regular Contributor
Take it for what is - a warning. You just need to make sure it doesn't ever get completely filled up.
Will this warning be permanent now?
RT-AC68U, 386.1_2
NVRAM usage: 64414 / 65536 bytes
JFFS: 4.64 / 62.75 MB
Uptime: 4 h

Warning: "Your router is running low on free NVRAM, which might affect its stability.
Review long parameter lists (like DHCP reservations), or consider doing a factory default reset and reconfiguring."
 
Last edited:

L&LD

Part of the Furniture
Not if you do what it suggests (and without restoring a saved backup config file afterward).
 

eibgrad

Very Senior Member
Review long parameter lists (like DHCP reservations)...

Isn't that the 64k question (pun intended :) )? What is actually eating up all that nvram? Based on prior comments, it seems users at least believe they do NOT have such long lists. And iirc, Merlin moved things like OpenVPN certs and keys to jffs (at one time, the most egregious of nvram consumers). So what in the world is consuming all this nvram space? Is it third-party scripts? Add-on features the user doesn't need or use? Just seems to me that's remains an open question.
 

Igor

Regular Contributor
Just seems to me that's remains an open question.
How to close the question?

Code:
size: 64345 bytes (1191 left)
931 nc_setting_conf
549 rc_support
524 dhcp_staticlist
488 custom_clientlist
460 dhcp_hostnames
272 filter_lwlist
248 wl0_maclist_x
247 wl_maclist_x
245 wl0_maclist
244 wl_maclist
233 wl1_acs_excl_chans_base
228 wl1_acs_excl_chans
205 wl1_chansps
176 wl1_maclist_x
173 wl1_maclist
166 subnet_rulelist
154 wan0_xroutes_ms
120 qos_rulelist
112 vlan_rulelist
92 1:pa5ga2
 
Last edited:

eibgrad

Very Senior Member
How to close the question?

Code:
size: 64345 bytes (1191 left)
931 nc_setting_conf
549 rc_support
524 dhcp_staticlist
488 custom_clientlist
460 dhcp_hostnames
272 filter_lwlist
248 wl0_maclist_x
247 wl_maclist_x
245 wl0_maclist
244 wl_maclist
233 wl1_acs_excl_chans_base
228 wl1_acs_excl_chans
205 wl1_chansps
176 wl1_maclist_x
173 wl1_maclist
166 subnet_rulelist
154 wan0_xroutes_ms
120 qos_rulelist
112 vlan_rulelist
92 1:pa5ga2

FWIW, here's my own top 20 list (RT-AC68U, 384.19).

Code:
size: 56341 bytes (9195 left)
1750 vpn_client1_cust2
1749 vpn_client_cust2
810 nc_setting_conf
544 rc_support
411 sshd_authkeys
131 wl1_chansps
120 qos_rulelist
92 1:pa5ga2
92 1:pa5ga1
92 1:pa5ga0
81 asus_device_list
72 bwdpi_app_rulelist
71 vpn_server2_ncp_ciphers
71 vpn_server1_ncp_ciphers
71 vpn_client5_ncp_ciphers
71 vpn_client4_ncp_ciphers
71 vpn_client3_ncp_ciphers
71 vpn_client2_ncp_ciphers
71 vpn_client1_ncp_ciphers
70 vpn_server_ncp_ciphers

Note, my router is one I'm using in the lab for testing purposes, so it's probably not representative of someone using the same router for their primary router. But it does have a configured OpenVPN client. And strangely these variables called vpn_client_cust2 and vpn_client1_cust2, which appear to contain some sort of cert or key (usually such things are stored in jffs). But I can't match them to anything in the OpenVPN client GUI. If it wasn't for those, I'd have 12,694 bytes left. Eliminate the SSH public key as well, and it's 13,105.

So it does appear that some of those "lists" in your top 20 are a contributing factor. But even if you eliminated them, that would save you ~ 3kbytes, leaving you w/ ~4k bytes. Far less than I'm showing with an otherwise comparable nvram.

All I can assume is that for YOUR particular router, it's different enough that it's overall consumption of nvram is unusually high, either because you have a lot of variables w/ small values, or just variables not found on other routers (the OP and I have the same router, so it would likely be the former in that case).

Anyway, it's difficult to know if there's a particular culprit here, or whether we just can't appreciate how much nvram is being consumed in total just due to natural growth of the firmware, and/or something affecting specific routers.
 

Morris

Senior Member
have you tried adding a USB stick so you can have virtual memory on the Swap drive?
 

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