[squid-users] Questions regarding COSS setup

Hi all,

I want to use COSS but I'm not sure if I understand all the options
right. So this is what I want:

Although our average object size is ca. 27 kB most of the files are much
smaller. This is the distribution of about 11 M files from one of our
Squids:
 <1kB: 19585 0,1%
 <2kB: 583402 5,2%
 <4kB: 4897854 44,3%
 <8kB: 1049084 9,4%
 <10kB: 145059 1,3%
 <20kB: 351615 3,1%
 <30kB: 182077 1,6%
 <40kB: 325084 2,9%
 <50kB: 597911 5,4%
 <60kB: 807344 7,3%
 <70kB: 742066 6,7%
 <80kB: 527370 4,7%
 <90kB: 333543 3%
 <100kB: 206064 1,8%
>100kB: 280574 2,5%

I want to let Squid do as less IO as possible. So I thought I set
"maximum_object_size_in_memory" to 4 kB and "max-size" for COSS to 3x
8kB = 24 kB. The rest goes into AUFS.

So my configuration lines would look something like this:

cache_dir coss /web/cache/1/coss/ 20480 max-size=24576
cache_dir coss /web/cache/2/coss/ 20480 max-size=24576
[...]
cache_dir aufs /web/cache/1/aufs/ 81920 290 256
cache_dir aufs /web/cache/2/aufs/ 81920 290 256
[...]

Help is needed with the following things:

- "--with-coss-membuf-size" compile-time option is set to 1 MB per
default. Does it make sense to change this value?

- How big should I make the COSS files? I thought about 20 GB on four
disks for COSS and 60 GB on the same disks for AUFS.

- How do I understand "block-size"? What values should I use? I can't
get my head around the docs in the Squid-Wiki.

- All other options for COSS seem to be for specific cases which don't
apply here(at least that's what I think). So leaving them at the default
values would be my choice.

Thanks for any help,

    Markus
Received on Mon Jan 25 2010 - 09:27:04 MST