[Users] OpenVZ on EL6 - weird network issue

[Michael Stauber]

Hi Pavel,

> Did you tried open-v-switch instead standard Linux bridges?

I actually wasn't aware of that one before you mentioned it.

I'm just starting to read the docs and specs of it and it looks indeed
very interesting.

Do you by chance have any specific pointers or docs how to set it up for
usage with OpenVZ? I'm willing to give it a shot, but with these client
systems I can't afford much in the way of experimenting. Taking the
bridge stack apart and replacing it with something else might be a
little too extreme, but I'll consider it as last resort. In any case I'd
like to avoid the usual beginner mistakes one could make when switching
to open-v-switch, so any tips and hints (or URLs to reading material)
would be appreciated.

As for Scott's suggestion with a cronjob with arp-seeds:

I did some digging and the network related shell scripts of OpenVZ are
quite enlightening there:

/etc/sysconfig/network-scripts/ifup-venet
/usr/libexec/vzctl/scripts/vps-functions

It appears that if I set up a cronjob that periodically runs ...

/etc/sysconfig/network-scripts/ifup-venet
/etc/sysconfig/network-scripts/ifcfg-br0

... then it'll handle the arp-seeds as well via the function vzarp() as
provided by /usr/libexec/vzctl/scripts/vps-functions.

I tried it on a test box and it didn't appear to have any negative
impact. Some debugging lines thrown in by me also showed me the exact
commands that these scripts use to do the arp-seeds. I can work with that.

I'll implement that on the three affected nodes and will see if it helps.

-- 
With best regards

Michael Stauber