xfs_freeze same as umount? How is that helpful?

[Linda Walsh <xfs@xxxxxxxxx>]

Greg Freemyer wrote:
> Conceptually it is typically:
> - quiesce system
----
        Um... it seems that this is equivalent to being
able to umount the disk?

When I tried xfs_freeze / fs_freeze got fs-busy -- same as I would
if I tried to umount it.

I thought the point of xfs_freeze was to allow it to be brought to
a consistent state without unmounting it?

Coincidentally, after trying a few freezes, the system froze.

Last message in log was 'fetchmail' (that might have been writing a
log to /home), had hung for 120 seconds...

That was all she wrote before the entire system 'froze'...


So shouldn't xfs_freeze work without having to to shut down every
process on it?  If not, then how is it different than umount?