Huge babeld.log

[Μανούσος Πουλινάκης]

I've been messing about with a couple of openwrt routers today and I found out that /var/log/babeld.log can get quite huge 

-rw-r--r--    1 root     root       1082664 Aug 23 20:47 babeld.log

mostly it is filled with 

Couldn't determine channel of interface eth0.3: Operation not supported.

Couldn't determine channel of interface eth0.4: Operation not supported.

Couldn't determine channel of interface eth0.5: Operation not supported.

I think it's because it's trying to find out on what wifi channel that interface is operating. But as you can see, this is a wired interface.

The reason this happens is because we have configured it in /etc/config/babeld.conf to be treated as a wireless interface (because an antenna is connected to it). But babeld thinks is a wireless interface that is physically present on the router.

Babeld tries to get the channel every few seconds (i think it's every time it sends a `hello`) so it fills the log quite quickly and I think /var/ is mounted on flash storage, so... 

Anyway, the solution I found is to add 

option channel noninterfering

to every interface entry in /etc/config/babeld.conf

I observed this on openwrt chaos calmer 15.05 and 15.05.1

Let me know of your thoughs, if you have any....

If i'm correct, maybe someone who has access, should update the wiki, (is it still online?) and in the process, use the new way of interface name definitions (as an option, see my example below). 

config interface 

        option ifname Rogdia

        option wired false

        option link_quality true

        option channel noninterfering

instead of 

config interface Rogdia

        option 'wired' 'false'

        option 'link_quality' 'true'

The one on the wiki is outdated, though still parseable. See the bottom of this page: https://wiki.openwrt.org/doc/uci/babeld

[Μανούσος Πουλινάκης]

Update: /var is actually a link to /tmp, so babeld log only fills up ram. but still... ram is precious ^_^