Linux不能格式化硬盘

一、情形：
机器上面有两块硬盘，其中一块可用状态，另一块不可用。之后对另一块分区、格式化。但是在格式化出现了错误。
[root@localhost ~]# mkfs.ext3 /dev/sdb1
mke2fs 1.39 (29-May-2006)
/dev/sdb1 is apparently in use by the system; will not make a filesystem here!
[root@localhost ~]# df -h

二、处理：
[root@localhost ~]# dmsetup status
ddf1_44656c6c202020201000006010281f0c359b9d3e3773cd05: 0 975699968 linear
[root@localhost ~]# dmsetup remove_all
[root@localhost ~]# mkfs.ext3 /dev/sdb1
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
61063168 inodes, 122096000 blocks
6104800 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
3727 block groups
32768 blocks per group, 32768 fragments per group
16384 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000
Writing inode tables: 1159/3727