Bad performance when accessing a lot of small files

[Alfred Perlstein]

* Alexandre Biancalana <biancalana at gmail.com> [071225 16:45] wrote:
> On 12/21/07, Alfred Perlstein <alfred at freebsd.org> wrote:
> 
> > Have you tried the 'noatime' mount option?  That should help.
> 
> Yeah, the zfs set atime=off was already done....
> 
> >
> > Can you provide a histogram of the count of files per directory?
> 
> Excuse-me, but I don't understand....

Distribution of files per directory, example:

1000 files in 9 dirs
1001 files in 12 dirs

find /path_to_root/ -type f | sed 's/\/[^/]*$//' | uniq -c | \
  awk '{print $1}' | sort -n | uniq -c

That will print out the number of files per dir.

   2 98
   3 102
   1 103
   2 105

Or something like that.



-- 
- Alfred Perlstein