格式化分区报错：The device apparently does not exist; did you specify it correctly?

hf001@hf001:/# mkfs -t ext4 /dev/sda4
mke2fs 1.42 (29-Nov-2011)
Could not stat /dev/sda4 --- No such file or directory

The device apparently does not exist; did you specify it correctly?

重启系统也可以，使用partprobe也可以

hf001@hf001:/# partprobe
hf001@hf001:/# mkfs -t ext4 /dev/sda4
mke2fs 1.42 (29-Nov-2011)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=4 blocks, Stripe width=4 blocks
136 inodes, 1048 blocks
52 blocks (4.96%) reserved for the super user
First data block=1
Maximum filesystem blocks=1310720
1 block group
8192 blocks per group, 8192 fragments per group
136 inodes per group

Allocating group tables: done                            
Writing inode tables: done                            

Filesystem too small for a journal
Writing superblocks and filesystem accounting information: done