[Samba] best filesystem choice for samba (was: new user cannotlogon)

[Malcolm Baldridge]

Quoting Mark Lidstone <mlidstone at bmtseatech.co.uk>:

> ARGH!  I'm wondering if airing thoughts about VFAT performance publicly
> was a good idea.

I doubt VFAT's case insensitivity would be worth dealing with its terrible
linear-search-time directory lookup methods.

The reason I suggested reiserfs (or ext3 with directory hashing) is to
reduce the high costs of locating a directory entry within a directory of
many (> 10,000) files.

msdos/vfat does not offer superior directory lookup times, and from my
limited testing, neither does NTFS.

ext2/ext3 in stock configuration is also slow, though it appears very recent
kernels/ext2fsutils offer an FFS-like "directory hashing" option which needs
a format-time decision to be made upon setting up the filesystem.

I have no knowledge about XFS or JFS and how they compare.  I know both are
"industrial" filesystems brought down from the Ivory Towers onto the
pipsqueak platforms.

As for "horror stories", well, each filesystem has had their respective
tales of misery and woe... ext3 had shocking and fatal dataloss bugs in the
adolescent versions of 2.4.x., and some RAID + reiserfs configs saw some
real wowsers as well.  From bug reports/changelogs, I've seen similar tales
of woe for XFS and JFS if you trigger just the right combination of things.

>From my own experiences, things have matured and stabilised with reiserfs
and ext3 to the point where using either is fine for my purposes.

The decision comes down to:

1) Do you need quotas?  If yes, you cannot use reiserfs.
2) Do you need ACLs?  If yes, only ext2/ext3 has well-tested seamless
support, though I think there are wildcat patches to bring this to XFS (and
maybe others) as well.  I'm not sure about the stability of this.

ext3 used with -O dir_index *MAY* provide better performance for large
directory list lookups, but I've never tested it.  It requires Linux 2.6 for
starters for the kernel-side stuff to actually support it properly. 
grepping the linux 2.4 source shows no mention of hashing b-trees or
dir_index options for ext[23].

This is a RECENT addition to ext3, and I don't think the support actually
exists within 2.4 yet.  I've seen mention of "special backported patches"
but this smells scarier to me than using filesystems which have been
seamlessly integrated for over a year or so now.

So in terms of viable performance-driven alternatives, I see it being
reiserfs, xfs, or jfs.

vfat/dos isn't faster, even with case insensitive semantics, for directory
sizes of 20,000 or more.

=MB=