[FreeBSD] 如何通过DUMP命令把一个LABEL保存为镜像文件

[weixin_38060626]

两个硬盘aacd0与aacd1，其中aacd0为系统盘，aacd1为数据盘，想通过dump命令把aacd0上的/、/usr、/var等分区分别保存为boot.img、usr.img、var.img，不过在操作时却不成功，单用户模式下也不行。

如下命令操作至第三步时即没有反应了！
#dump -f- /usr > usr.img
DUMP: WARNING: should use -L when dumping live read-write filesystems!
DUMP: Date of this level 0 dump: Thu May 8 10:47:28 2008
DUMP: Date of last level 0 dump: the epoch
DUMP: Dumping /dev/aacd0s1e (/usr) to standard output
DUMP: mapping (Pass I) [regular files]
DUMP: mapping (Pass II) [directories]
DUMP: estimated 5590901 tape blocks.
DUMP: dumping (Pass III) [directories]

这个命令搞成这样了，好象也没有成功，不知如何保存成一个文件。
dump -f usr.img /usr
DUMP: WARNING: should use -L when dumping live read-write filesystems!
DUMP: Date of this level 0 dump: Thu May 8 10:52:00 2008
DUMP: Date of last level 0 dump: the epoch
DUMP: Dumping /dev/aacd0s1e (/usr) to usr.img
DUMP: mapping (Pass I) [regular files]
DUMP: mapping (Pass II) [directories]
DUMP: estimated 5637234 tape blocks on 143.82 tape(s).
DUMP: dumping (Pass III) [directories]
DUMP: Closing usr.img
DUMP: Change Volumes: Mount volume #2
DUMP: Is the new volume mounted and ready to go?: ("yes" or "no") yes
DUMP: Volume 2 begins with blocks from inode 383303
DUMP: Closing usr.img
DUMP: Change Volumes: Mount volume #3
DUMP: Is the new volume mounted and ready to go?: ("yes" or "no") yes
DUMP: Volume 3 begins with blocks from inode 1039095
DUMP: dumping (Pass IV) [regular files]
DUMP: Closing usr.img
DUMP: Change Volumes: Mount volume #4
DUMP: Is the new volume mounted and ready to go?: ("yes" or "no") yes
DUMP: Volume 4 begins with blocks from inode 117840
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本人对dump与restore不太熟悉，man看了很长时间也不知所云，请各位老大指教，谢谢！