[CentOS] wich filesystem to store > 250E6 small files in same or hashed dire

Sat Mar 12 14:12:40 UTC 2011
Simon Matter <simon.matter at invoca.ch>

> Hi
>
> I need to store about 250.000.000 files. Files are less than 4k.
>
> On a ext4 (fedora 14)  the system crawl at 10.000.000 in the same
> directory.
>
> I tried to create hash directories, two level of 4096 dir = 16.000.000
> but I had to stop the script to create these dir after hours
> and "rm -rf"  would have taken days ! mkfs was my friend
>
> I tried two levels, first of 4096 dir, second of 64 dir. The creation
> of the hash dir took "only" few minutes,
> but copying 10000 files make my HD scream for 120s ! I take only 10s
> when working in the same directory.
>
> The filenames are all 27 chars and the first chars can be used to hash
> the files.
>
> My question is : Which filesystem and how to store these files ?

Did you try XFS? Deletes may be slow but apart from that it did a nice
jobs when I last used it. But we had only around 50.000.000 files at the
time.
However, also ext3 worked quite well after *removing* dir_index.

Also, did you run a x86_64 kernel? We were having all kind of troubles
with big boxes and i686-PAE kernel, because direntry and inode caches were
very small.

Simon