What happens when syslog gets blocked?

We recently had a problem with a database where the /var filesystem  
got corrupted. This appears to have seriously impacted the ability of  
STDERR from Postgres to get put out to disk, which ended up blocking  
backends.

Because of this we want to switch from using STDERR to using syslog,  
but I'm not sure if syslog() can end up blocking or not. I know that  
(by default) syslog uses UDP when logging to an external syslog, but  
what happens if you're using the local syslog? Is it still UDP or  
some other mechanism that could potentially block the backends?

Also, I think we should either warn users about STDERR (and  
presumably the CVS logging) or change things so that something that  
breaks logging doesn't block backends.
-- 
Decibel!, aka Jim C. Nasby, Database Architect  decibel@decibel.org
Give your computer some brain candy! www.distributed.net Team #1828