What does "HAMMER UPGRADE" flag means during hammer cleanup

[Siju George]

Hi,

While running hammer cleanup a new pfs i created and mounted showed

cleanup /vms/vm-archlinux    - HAMMER UPGRADE: Creating snapshots
        Creating snapshots in /var/hammer/vms/vm-archlinux
 handle PFS #8 using /var/hammer/vms/vm-archlinux
           snapshots - run
               prune - run
           rebalance - run..
             reblock - run....
              recopy - run....

where as the old pfses does not show the  "HAMMER UPGRADE" flag

cleanup /usr                 - handle PFS #3 using /var/hammer/usr
           snapshots - run
               prune - run
           rebalance - run..
             reblock - run....
              recopy - run....

There is no need to upgrade the pfs because it is actuall on hammer version 4.
So is there any thing I need to know about this falg? :-)

thanks

--Siju