Comment # 18 on bug 1174056 from Lewis Wolfgang

SOLVED!

In trying to figure out what values to use for sunit and swidth I compared our
current blockdev output with other older production systems and noticed the
1048576 value for iomin.  That rang a bell!  When using the Broadcom GUI to
create the RAID volumes, one of the choices was for a stripe size, and offered
sizes from 16K to 1M. These two volumes were created with the 1M choice
selected.  So, I deleted the existing two volumes, then re-created them leaving
the stripe size at the default of 256K.  The XFS filesystems were then
re-created and all mounted as expected!  The immediate problem is solved!  

But I expect that we'll see this problem again when our production boxes are
upgraded to 15.2, so this dialog will help us to prepare for that
unpleasantness.

It would be nice if there was a kernel command-line option to turn off strict
XFS parameter checking, but I realize that it probably goes deeper than that.

Thanks for your help, Anthony.  I'll save your process, I think we'll be
needing it before too long.