[Ocfs2-users] OCFS2 and huge (> 50TB) partitions

[Patrick J. LoPresti]

Hello.  I am experimenting with OCFS2 on a brand new 10GigE iSCSI SAN.
 It looks pretty good so far -- I am seeing sustained (direct I/O)
read speeds of 1300+ MB/sec -- except for one problem:  I need a
single partition to hold much more than 16 TB.

I am running into the same issue described by this thread:

http://www.mail-archive.com/ocfs2-devel@oss.oracle.com/msg04740.html

That is, even though I created a partition with "mkfs.ocfs2 -C 1M -J
block64 --fs-feature-level=max-features..." and mounted it with "-o
inode64", it still fails with:

"Volume might try to write to blocks beyond what jbd can address in 32 bits."

>From the description on that thread, this is an obsolete check in
fs/ocfs2/super.c.  But when I look at the kernel source for 2.6.32.15
and 2.5.35-rc2, I see that the check is still there.  I believe this
means that partitions larger than 16TB will not work on any released
kernel.

Is my understanding correct that this check prevents large partitions
from working at all?  Do the OCFS2 developers intend to remove it?
When?

I am doing my testing on Suse Linux Enterprise 11 Service Pack 1,
which is based on kernel 2.6.32 and ocfs2-tools 1.4.3.  My research
suggested these software levels should support large partitions.  I do
intend to take this up with Suse, but I was hoping there was an
official patch I could point them to...

Thanks!

 - Pat