WordPress MU

Hi,

ok, I surrender. Just after I came back from a weekend, blogs went crazy. Load time of some of them is approx. 40sec while others work perfectly fine.
At beginning I thought that it's a plugin problem (WhassUp suddenly caused pages to crash), but after turning them off, problem still remains.

-About 1/4 of blogs are acting strange (skin and domain don't matter)
-Not only content itself, but Admin Panel of those is terribly slow as well.
-Firebug shows that "GET domain.tld" required 40sec. to run, while other elements are normal (in ms).
-Domains ping is ok (in ms).
-Error log shows small problem with open_basedir to mu-plugins (but plugins are turned off + safe mode off)
-Random blogs affected. Not only on parked domains, but also on subdomains. Various skins.

All should be perfectly fine. It's the same configuration as on Friday, yet not working as it should be.

Here are some examples (in japanese only, sorry)

working:
http://kyoto-tales.net (main blog)
http://nana.kyoto-tales.net/
http://e-koito.com/ (parked)

frustrating ones:
http://kyoyokai.com/ (parked)
http://mateusz.kyoto-tales.net/
http://eigamura.kyoto-tales.net/

I run out of possibilities. Don't know even what might be wrong (randomness excludes quite many options that I'm aware of).
If nothing helps there will be reinstallation. But it's not a perfect solution (+ quite painfull as few things are modified)

Any help appreciated.
Thanks in advance
A.

WordPress 1.5.1, VPS

Kill me, but I've restarted apache and it seems to be working now.
Er, how to delete posts in here? ;D

Akashic you probably are running out of ram from to many Apache processes running, which were killed when you restarted. It might be time to poke around the forums for hints on how to optimize you site - i.e. install eAccelartor or Zend to compile php pages and make sure that you have page caching installed.

Thanks for the tip, but resources are still sufficient. Apparently my provider changed nameserver's IP and probably VPS had some troubles while it wasn't restarted.