Disc access every 15 sec / firewall+FTP

Hello,

I've been a very happy user of squid 2.2 STABLE 4 for a few weeks -
especially the offline option is just what I needed! - but I still have
a few problems:

I'm running squid as a local proxy on my laptop, and have taken great
care with my Linux setup to avoid regular disc accesses (e.g. by the
update daemon) to allow the harddisc to spin down.

However, squid seems to access the HD every 15 seconds, although
sometimes it also stops for a while. Is there a way to turn off the
accesses completely?

Also, I've set up a firewall (mainly to acquaint myself with ipchains).
I've noticed that FTP fetches made by squid always seem to use active
mode FTP; at least many packets arrive with arbitrary port numbers >1024
for both sender and receiver. Is there a way to make squid use passive
mode FTP or do I really have to allow through all incoming TCP packets
on nonstandard ports?

Many thanks for your help, and for this wonderful piece of software!

Cheers,

  Richard

-- 
  __   _
  |_) /|  Richard Atterer
  | \/�|  http://www.in.tum.de/~atterer/                      raFS V1.16
  � �` �
If they give you ruled paper, write the other way    -- Juan Ram�n Jim�nez