Re: [squid-users] More on - How does (AUFS) squid decide which c

On 24-Aug-07 My Secret NSA Wiretap Overheard Henrik Nordstrom Saying :
> On fre, 2007-08-24 at 12:41 -0700, Nicole wrote:
>>
>> Here is an example from another server. As you can see, /cache0 seems to be
>> getting very little of the data on 2 different servers. Found out of the
>> range
>> I would assume based on their storage size. I am curious if my choices for
>> L1/L2
>> effect what sized files go where? (like Coss seems to do)
>
> L1/L2 does not have any effect on cache_dir selection. Just how many
> files the "*ufs" stores place in each subdirectory.
>
>> Also, I think this has been asked before, but what criteria should be used
>> to
>> decide the settings for L1/L2? I think the defaults are based on much
>> smaller
>> disks, but does that matter?
>
> l2 = 256

 So, this should always be the same size?

> L1 = at least cache_dir size * 2 / 256 / 256 / 13KB, or ca cache_dir in
> GB * 2. (13 KB is the estimated average object size)

 ca?

 I guess I am missing something?
 90000 * 2 / 256 / 256 = 2.746582 / 13000 = .0002112 ??

 Could you provide an example or 2?

# AUFS
# cache_dir aufs Directory-Name Mbytes L1 L2 [options]
cache_dir aufs /cache0 24000 32 256
cache_dir aufs /cache1 90000 64 768
cache_dir aufs /cache2 90000 64 768
cache_dir aufs /cache3 90000 64 768

> Note: You can not change L2 without erasing the cache. But you can
> change L1 as long as it's been big enough to fit the stored content..
>
>> It would be great if some math for this was in
>> the .default file to help. It seems like my testing of different sizes has
>> resulted in different amounts of storage utilization some how.
>
> It should not have any effect, other than that it L1 is too small then
> Squid stores more than L2 files in each subdirectory which may have a
> slight negative performance impact depending on the kind of filesystem
> used..
>
>
> Regards
> Henrik

 Sorry to be so dense at the moment.
 Thank you so much!

  Nicole

--
                     |\ __ /|   (`\            
                     | o_o  |__  ) )           
                    //      \\                 
  -  nmh@daemontech.com  -  Powered by FreeBSD  -
------------------------------------------------------
 "The term "daemons" is a Judeo-Christian pejorative.
 Such processes will now be known as "spiritual guides"
  - Politicaly Correct UNIX Page