The disk drive for /mnt/st is not yet ready or not present
 

hi
I try make a encrypted filesytem on /dev/sda3
next i use cryptsetup and find this issue that add
st /dev/sa3 non luks to /etc/crypttab.
othet i add /dev/mapper/st /mnt/st ext3 defaults 0 1 to /etc/fstab
now i want when restart my pc enter passphrase and dont see this error
"The disk drive for /mnt/st is not yet ready or not present"
I waite for answer

1- apt-get install cryptsetup
2- cryptsetup luksFormat /dev/sda3
3- cryptsetup luksOpen /dev/sda3 st
4- mkfs.ext3 /dev/mapper/st
5- st /dev/sda3 non luks to /etc/crypttab
6- mkdir /mnt/st
7- /dev/mapper/st /mnt/st ext3 defaults 0 1 to /etc/fstab
8- restart

In time boot ,this error print to desktop.
"The disk drive for /mnt/st is not yet ready or not present"

I do this works .eny person exit help me