OK,
I have found it - and i think this will affect a few other people too so here are the details as clear as i can explain them:
A few months ago i installed the snort/acid contribs from Ari Novikoff (
http://www.marari.net/). The version i used is the current one -
http://www.marari.net/downloads/snort/sme-acid-2.0.0-1ari.noarch.rpm.
I encountered the logrotate problem as detailed in this thread :
http://forums.contribs.org/index.php?topic=9231.msg35102#msg35102however until just now i didn't realise that if there is an error as logrotate steps through the files in /etc/logrotate.d/ the logrotate process stops at the point of the error.
So since the logrotate.d files are processed in alphnumeric order, and /etc/logrotate.d/snort was failing with an error, logrotate was never getting to the next file - /etc/logrotate.d/squid, and THAT is why my squid access.log was 1.3GB!
I fixed the /etc/logrotate.d/snort file, ran /etc/cron.daily/logrotate manually, and hey presto my squidlogs got rotated just fine.
Thanks to grand-pa for making me think in a different direction - I noticed it was only the squid logs that were having this problem, and connected that with the only thing I learned in school - which is that s
Q comes after s
N in the alphabet!
