[squid-users] Re: Adding Another HardDisk and the read_only option

On Thu, 2 Oct 2008 12:09:09 +0300
"Mr. Issa\(*\)" <xnixguy_at_gmail.com> wrote:

> Hello mates,
>
> Well i have added to separate hard disks (200GB hd and 500GB hd) and
> added them in the cache_dir but i noticed that squid Uses the hardisk
> with MORE disk space and leaves the second one epmty... why?

There are two store_dir_select_algorithm settings: round-robin and the
default least-load. The latter is supposed to select the cache with
the least-load, but on relatively lightly-loaded systems it picks the
one with the most free-space, so you expect the 500GB drive to fill-up
to 300GB or so before the smaller starts getting any.

My memory is a little vague here, but my recollection is that neither
algorithm works optimally when the caches are of different sizes.
I think Round-robin puts equal amounts in all caches, without
weighting them; least-load always favours the larger cache
because the low-water mark gives it more free space.

If you want to tweak it once all the caches have filled, you can play
around with the min and max object size for each cache to balance them
out.
Received on Sat Oct 04 2008 - 22:49:21 MDT