EVMS, LVM, LVM2, XFS, ext3 on FC3

[David Kewley]

I'm looking at building several multi-TB arrays in an academic research 
environment.  So far I've been heading toward FC3 (or possibly RHEL4 when 
it's released), EVMS, and XFS.

I've seen little or no mention of EVMS in the Fedora and RHEL communities, and 
I'm wondering why that is.  From reading websites & mailing list archives, it 
seems to me like EVMS is more mature than LVM2, and more fully-featured than 
either LVM or LVM2.  I've not actually used any of the three yet.

Today I'm patching the FC3t2 kernel (541) with the patches (mostly DM patches) 
recommended on the EVMS website http://evms.sourceforge.net/install/, and 
it's going quite smoothly.  So far only the first patchfile in the udm1 
patchset didn't apply, because it's already applied in FC3t2 kernel 541.  A 
similar patching attempt yesterday on FC1 was miserable (I expect no one will 
be surprised at that :).

Is there a good reason to use LVM or LVM2 rather than EVMS?  Is there a reason 
EVMS isn't included in FC?

On to filesystems.  I saw some commentary by Arjan on the RHEL4 beta list 
http://www.redhat.com/mailman/listinfo/nahant-beta-list suggesting that there 
is no good, known reason to use XFS in RHEL4 (and presumably FC3?), because 
ext3 has been patched to provide significantly better performance, and online 
resize of ext3 is being actively worked on.  Indeed those are the two obvious 
issues that I care about, so I'm considering going with ext3 rather than XFS.

Can anyone think of a reason to use XFS over ext3, even with the improvements 
that Arjan mentioned?  Maybe XFS scales better still, or provides a 
significant advantage in filesystem size on 64-bit architectures, compared to 
ext3?

David