[Samba] Using ZFS Case insensitive filesystems with Samba

[Jeremy Allison]

On Tue, Feb 25, 2014 at 10:42:45PM +0000, Jonathan Buzzard wrote:
> On 25/02/14 21:08, Jeremy Allison wrote:
> >Here's something I learned when working with the FreeNAS folks :
> >
> >ZFS can be configured to be case insensitive when
> >you create the filesystem (NOTE - cannot be altered
> >*after* the filesystem is created).
> >
> >zfs create -o casesensitivity=insensitive filesystem
> >
> >https://www.freebsd.org/cgi/man.cgi?query=zfs&apropos=0&sektion=0&manpath=FreeBSD+8.1-RELEASE&format=html
> >
> >Once you've done this set the following in the
> >share definition in your smb.conf :
> >
> >[ZFSSHARE]
> >	path = /foo
> >	case sensitive = true
> >
> >and Samba will go *much* faster for
> >directories with large numbers of files
> >(we don't have to scan the directory on
> >every cache miss) !
> >
> 
> Do you have a unit test for this to show it going faster? The reason
> I ask is there is a GPFS option for the file system
> 
>     allowSambaCaseInsensitiveLookup
> 
> which I think does something similar but IBM don't document it. It's
> one of their magic/secret options. A ready built test case would be
> useful in working out how it works/what it does...

It's one of the customer test cases Microsoft used
to use to show how bad Samba performs in a comptitive
situation, but we don't have a unit test directly :-).

It's easy to reproduce. Create a directory with 1 million
files, then try and open a non-existing file for read :-).

Jeremy.