ubuntu 无法格式化磁盘

格式化磁盘时出现了错误：

$ mkfs.ext4 /dev/sdc
/dev/sdc contains a LVM2_member file system
Proceed anyway? (y,n) y
/dev/sdc is apparently in use by the system; will not make a filesystem here!

解决办法：

$ dmsetup status
$ dmsetup remove_all
$ dmsetup status
No devices found

出现上面的结果后，再进行格式化就成功了：

$ mkfs.ext4 /dev/sdc

mke2fs 1.42.13 (17-May-2015)
/dev/sdc contains a LVM2_member file system
Proceed anyway? (y,n) y
Creating filesystem with 3417964544 4k blocks and 427245568 inodes
Filesystem UUID: 0774e265-28c4-40bd-82bd-51ca9fb46bbf
Superblock backups stored on blocks:
    32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
    4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
    102400000, 214990848, 512000000, 550731776, 644972544, 1934917632,
    2560000000

Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

出现上述情况代表格式化成功。