Re: [squid-users] Can a cache be "too big"?

yes.
1) the index is in memory and needs 10-20 MB index in memory for each GB on disk
2) the housekeeping of the index costs more CPU cycles for a larger cache
3) the housekeeping of the cached objects on disk costs time and grows when the cache is
larger. Can be minimised by having cache_swap_low 92 and cache_swap_high 93.

The system has 2 GB memory, assuming that the system is dedicated for Squid
you need 400 MB for the OS, leaving 1.6 GB for Squid.
A safe value for cache_mem would be 500 MB

There are many tuning parameters.
The best one is to have more disks.

Marcus

Marcello Romani wrote:
> Ralf Hildebrandt ha scritto:
>> * Ralf Hildebrandt <Ralf.Hildebrandt_at_charite.de>:
>>
>>> maximum_object_size 50 MB
>>> cache_dir diskd /squid-cache 45000 16 16
>>> request_header_max_size 15 KB
>>> request_body_max_size 750 MB
>>>
>>> The machine is 32 bits, MemTotal: 2060960 kB
>>
>> Some stats from before "the purge":
>>
>> 1.4Mio cached objects
>> 42GB Cache size
>>
>
> Could it be that cache_mem + memory required to manage 42GB of cache
> caused the squid process to be swapped ?
>
Received on Wed Jul 21 2010 - 13:57:06 MDT