[SLL] limit on number of files in a directory and hashed dir vs. flat dir file access time

[Rob Smith]

On 10/31/07, Ana <christiana at hipointcoffee.com> wrote:
> Here's an interesting thread on the topic.
>
> http://linux.derkeiler.com/Mailing-Lists/Fedora/2005-07/3279.html

"I think this
indicates that in my current 2.6.12 FC3 kernel using Ext3 the directory
data structure is still a list and not a tree. "

In FC3, you have to specify the dir_index ext3 option, in newer
distros, it's on by default. This can significantly speed up the
process.

My test results (Create, ls, rm)
1000 files
0m1.840s
0m0.005s
0m0.028s

10000 files
0m18.474s
0m0.019s
0m0.203s

100000 files
5m2.624s
0m0.400s
0m2.482s

Keep in mind, I don't consider this a valid test (Drive cache changes,
inode layout and free sections, etc), I'm just pointing out that he
likely didn't have the dir_index enabled which threw his results off.

~Rob