On Thursday 28 November 2002 13.32, Hermann Strassner wrote:
> If you have too less L-1 directories, i don`t really know if Squid
> put more than 256 files in one directory or if it uses the cache
> only partially.
Squid then wraps over on the first L1 directories as needed to fit all
the files in the cache.. the math for finding the correct directory
is modulo the number of configured directories.
The issue of the L1 and L2 parameters is mainly to keep each L2
directory in a reasonable size to avoid excessive directory searches
in UFS type filesystems storing directories as "files" where the
search time within a directory is linear to the amount of files
within the directory.
The L1 and L2 parameters are also related to a slow rate periodic
cleaning process walking your cache and doing garbage collection in a
L2 directory at a time (aim is 24 hours per cleaning round). Possibly
due to this cleaning odd negative performance effects is seen with
large L2 directories even if the actual underlying filesystem is very
efficient in managing directories (i.e. reiserfs) so it is
recommended to always keep these at the default of no more than 256
files per L2 directory.
Regards
Henrik
Received on Thu Nov 28 2002 - 18:57:36 MST
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