Re: [squid-users] squid / swap usage.

This isn't terribly surprising. Squid requires about 10MB or memory per
GB or cache_dir configured. So if you're using most of that 216GB for
cache_dirs, you're going to eat all of your memory just dealing with the
in-core object index, leaving no room for anything else. At this time I
won't configure anything with more than 108GB of disk space (6 x 18GB
15k RPM, to be specific), because Intel boxes can't go over 4GB of RAM,
and performance would suffer if we used much more than that.

On our 2GB RAM boxes, I configure about 45GB total cache_dir or less.
Much more than that can lead to performance degradation. If your box
can handle more memory, you can probably make more use of your disks by
upgrading RAM.

As for your question "Squid doesn't like disks that large?"...Squid
doesn't care how big your disks are, but it does have to have enough RAM
to index them. And because of OS-level disk caching, your box will
perform better with smaller cache_dir configurations to some extent.

So shrink those partitions a bit, or get some more RAM. It is pretty
cheap these days, though I don't know if you can use commodity parts in
your Ultra 250.

orko wrote:
> Hey
>
> I just have a query regarding squid's swap usage. We're running squid in
> a fairly high load environment, and we're finding that we can't let
> squid to utilise more than 20% of the available disk without it going
> /really/ heavily into swap and killing the performance.
>
> one box (for example) is an ultra 250 with an A1000 disk array (6 x
> ~36gb), 2gb memory running solaris 8. When squid initially starts, the
> responses times are quick, but once it finishes rebuilding its store,
> the responses times sky rocket and squid by then is consuming >1gb of
> the box's swap. Is the answer simply that squid doesn't like disks that
> large?
>
> gory details: squid 2.4 stable 4.
> configure opts: --enable-async-io, --enable-snmp, --enable-dlmalloc,
> - --enable-poll, --enable-removal-policies="heap lru"
> cache_mem 80
> cache_dir aufs /cache/00 10000 16 256
> cache_dir aufs /cache/01 10000 16 256
> ..etc
> [priority_paging enabled, with 32768 FD's]
>
> let me know if you need more info.
> any advice is muchly appreciated.
>
>
>

-- 
Joe Cooper <joe@swelltech.com>
http://www.swelltech.com
Web Caching Appliances and Support