执行一下该命令：
[root@linuxidc~]# partprobe
Warning:WARNING: the kernel failed to re-read the partition table on /dev/sda (Deviceor resource busy). As a result, it maynot reflect all of your changes until after reboot.
Warning:WARNING: the kernel failed to re-read the partition table on /dev/sdb (Deviceor resource busy). As a result, it maynot reflect all of your changes until after reboot.
Warning:Unable to open /dev/sr0 read-write (Read-only file system). /dev/sr0 has been opened read-only.
Warning:Unable to open /dev/sr0 read-write (Read-only file system). /dev/sr0 has been opened read-only.
Error:Invalid partition table - recursive partition on /dev/sr0.
然后执行格式化，就OK了，如果还提示出错，重启之后再执行格式化就可以了。
[root@linuxidc~]# mkfs -t ext4 /dev/sda7
mke2fs1.41.12 (17-May-2010)
Filesystemlabel=
OStype: Linux
Blocksize=4096 (log=2)
Fragmentsize=4096 (log=2)
Stride=0blocks, Stripe width=0 blocks
64384inodes, 257032 blocks
12851blocks (5.00%) reserved for the super user
Firstdata block=0
Maximumfilesystem blocks=264241152
8block groups
32768blocks per group, 32768 fragments per group
8048inodes per group
Superblockbackups stored on blocks:
32768, 98304, 163840, 229376
Writinginode tables: done
Creatingjournal (4096 blocks): done
Writingsuperblocks and filesystem accounting information: done
Thisfilesystem will be automatically checked every 35 mounts or
180days, whichever comes first. Use tune2fs-c or -i to override.