mkfs 拒绝格式化声称已安装的设备，但实际上并未安装

Question

这就是问题：

root@ip-10-126-247-82:~# mkfs.ext4 /dev/xvda3
mke2fs 1.41.14 (22-Dec-2010)
/dev/xvda3 is mounted; will not make a filesystem here!

这是调试：

root@ip-10-126-247-82:~# mount
/dev/xvda1 on / type ext4 (rw)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)

此外，设备 /dev/xvda2 内核将重新格式化，xvda1、xvda2、xvda3 是不同的设备

root@ip-10-126-247-82:~# ls -la /dev/xvda*
brw-rw---- 1 root disk 202, 1 2011-12-21 18:54 /dev/xvda1
brw-rw---- 1 root disk 202, 2 2011-12-22 10:33 /dev/xvda2
brw-rw---- 1 root disk 202, 3 2011-12-21 18:54 /dev/xvda3


root@ip-10-126-247-82:~# cat /proc/partitions 
major minor  #blocks  name

 202        1   10485760 xvda1
 202        2  356485632 xvda2
 202        3     917504 xvda3

它不会格式化 xvda1 （正确）

root@ip-10-126-247-82:~# mkfs.ext4 /dev/xvda1 
mke2fs 1.41.14 (22-Dec-2010)
/dev/xvda1 is mounted; will not make a filesystem here!

它将格式化 xvda2 （正确）

root@ip-10-126-247-82:~# mkfs.ext4 /dev/xvda2
mke2fs 1.41.14 (22-Dec-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
22282240 inodes, 89121408 blocks
4456070 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=0
2720 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks: 
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
        4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968

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

This filesystem will be automatically checked every 36 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.

它不会格式化 xvda3 （不正确）

root@ip-10-126-247-82:~# mkfs.ext4 /dev/xvda3
mke2fs 1.41.14 (22-Dec-2010)
/dev/xvda3 is mounted; will not make a filesystem here!

- 编辑：

按照 @Janne Pikkarainen 的建议添加 lsof debug：

root@ip-10-126-247-82:~# lsof -n | grep '202,3'
root@ip-10-126-247-82:~# lsof -n | grep 'xvda3'
root@ip-10-126-247-82:~# 

Answer 1

通过使用switch in可以在/etc/mtab根本不显示任何东西的情况下安装某些东西。-nmount

是否lsof -n | grep xvda3返回一些东西？