Persistent mount for luks with unlock Key

creating a encrypted disk with luks

our  Little problem here to mount a encrypted disk  automatically on boot

so no need to enter the pass for mounting but this risky if the machine theft happen because we will use a key inside the system and it will be leaked if our machine stolen

so lets do it first we have to create a key and add it  our partition

to create a key

[root@localhost ~]# dd if=/dev/random of=/root/key bs=4096 count=1
0+1 records in
0+1 records out
113 bytes (113 B) copied, 0.000462577 s, 244 kB/s
[root@localhost ~]# cat /root/key
y��]da�0�k�yhv�A��l�fn���ZÇ�_i)SK��D�Y�6ó�S��w���;�V�����,���+"���OE����{�[hf�
                                                                              �OR�
[root@localhost ~]#

don’t forget it to set key permission to be 600

now we need to tell our luks partition to use this key

[root@localhost ~]# cryptsetup luksAddKey /dev/sdb1 /root/key
Enter any passphrase:
[root@localhost ~]#

now we need to make it available in device mapper

to use encrypted disks while boot there is a crypt tab

vi /etc/crypttab

crypted1 /dev/sdb1 /root/keyfirst field is the device mapper name

the second one is the disk partition

third is the key file

[root@localhost ~]# vi /etc/fstab

/dev/mapper/crypted1    /mnt/crypted1           ext4    defaults        0 0

as u can see we put the device mapper name  that we used it in crypttab file and normal mount

reboot the system and enjoy it