DragonFly - hammer version-upgrade

VMware Fusion 上で、DragonFly を / 領域を hammer にして利用。（/boot は ufs）
hammer コマンドをぺちぺち叩いていたらバージョンが確認でき、バージョンアップもできるようなのでいざ実行。
（バージョン 2 -> バージョン 3 へ。あまりよくわかってない）

% hammer version /
min=1 wip=5 max=4 current=2 description="New directory entry layout (DragonFly 2.3+)"
available versions:
    1   NORM    First HAMMER release (DragonFly 2.0+)
    2   NORM    New directory entry layout (DragonFly 2.3+)
    3   NORM    New snapshot management (DragonFly 2.5+)
    4   NORM    New undo/flush, faster flush/sync (DragonFly 2.5+)
% hammer version-upgrade  / 3
hammer version-upgrade ioctl: Operation not permitted
% sudo hammer version-upgrade  / 3
Password:
hammer version-upgrade: succeeded
NOTE!  Please run 'hammer cleanup' to convert the
/snapshots directories to the new meta-data
format.  Once converted configuration data will
no longer resides in /snapshots and you can
even rm -rf it entirely if you want.

言われたとおりに cleanup を実行

% sudo hammer cleanup
cleanup /                    -(migrating)  (6 snapshots)index 6
 HAMMER UPGRADE: Moving snapshots
        Moving snapshots from /snapshots to /var/hammer/root
 handle PFS #0 using /var/hammer/root
           snapshots - run
               prune - run
           rebalance - run..
             reblock - run....
              recopy - skip
cleanup /var                 -(migrating)  (6 snapshots)index 6
 HAMMER UPGRADE: Moving snapshots
        Moving snapshots from /var/snapshots to /var/hammer/var
 handle PFS #1 using /var/hammer/var
           snapshots - run
               prune - run
           rebalance - run..
             reblock - run....
              recopy - skip
cleanup /tmp                 -(migrating)  HAMMER UPGRADE: Moving snapshots
        Moving snapshots from /tmp/snapshots to /var/hammer/tmp
 handle PFS #2 using /var/hammer/tmp
           snapshots - disabled
               prune - run
           rebalance - run..
             reblock - run....
              recopy - skip
cleanup /usr                 -(migrating)  (6 snapshots)index 6
 HAMMER UPGRADE: Moving snapshots
        Moving snapshots from /usr/snapshots to /var/hammer/usr
 handle PFS #3 using /var/hammer/usr
           snapshots - run
               prune - run

(snip)

% hammer version /
min=1 wip=5 max=4 current=3 description="New snapshot management (DragonFly 2.5+)"
available versions:
    1   NORM    First HAMMER release (DragonFly 2.0+)
    2   NORM    New directory entry layout (DragonFly 2.3+)
    3   NORM    New snapshot management (DragonFly 2.5+)
    4   NORM    New undo/flush, faster flush/sync (DragonFly 2.5+)

無事に完了した。

負荷がそれなりにかかっている、実サービスしているような環境下で実行した場合にも問題なくできるのかな。