Filestore directory splitting (ZFS/FreeBSD)

[Willem Jan Withagen <wjw@digiware.nl>]

Hi,

I'm running some alrger tests with ceph-fuse on FreeBSD, and noticed
that I start to run into directory splitting I think?
I just Rsynced my full src and ports tree into it, which is like >
1.000.000 small files.
At least I saw a rather large number of directories with relatively few
files in them.

I know from UFS that large directories used to be a problem, although
some of the issues on FreeBSD have been fixed long ago.

So can anybody explain the rationale behind this process and give a bit
of a feeling why we start splitting at 320 files??

FreeBSD's filestore runs of ZFS, and From waht I've seen thusfar is that
ZFS has a different (better) behaviour with large directories.
(I once ended up with > 1.000.000 security cam pictures in one
directory, and that still was sort of workable.)

So has there been any testing to quatify the settings? And how would I
be able to determine if ZFS deserves better/larger settings?

--WjW