在ubuntu 10.04 服務器上掛載移動硬盤，發現總是無法掛載成功。報錯：
mount: /dev/sdc1 already mounted or /opt/mnt/ busy
格式化化分區時系統報錯/dev/sdc1 is apparently in use by the system; will not make a filesystem here!
解決辦法:
root@GLWW032:/# dmsetup status
35000000000000001: 0 7814037167 multipath 2 0 0 0 1 1 A 0 1 0 8:32 A 0
36b083fe0d46350001c6c2a4504ba1041:
35000000000000001-part1: 0 7814037100 linear
root@GLWW032:/# dmsetup remove_all
root@GLWW032:/# dmsetup status
No devices found
root@GLWW032:/# mount /dev/sdc1 /mnt
man 信息 ： dmsetup - low level logical volume management
dmsetup manages logical devices that use the device-mapper driver. Devices are created by loading a table that specifies a target for each sector (512 bytes) in the logicaldevice.
The first argument to dmsetup is a command. The second argument is the logical device name or uuid.