====== LUKS ======
Naplnit disk náhodnými daty:

**~$ sudo dd if=/dev/urandom of=/dev/sda bs=4M status=progress**
<code>
238468+0 záznamů přečteno
238467+0 záznamů zapsáno
1000204886016 bajtů (1,0 TB, 932 GiB) zkopírováno, 29102,6 s, 34,4 MB/s
</code>

Vytvořit partition (GPT):

**~$ sudo gdisk -l /dev/sda**
<code>
GPT fdisk (gdisk) version 1.0.3

Partition table scan:
  MBR: not present
  BSD: not present
  APM: not present
  GPT: not present

Creating new GPT entries.

Command (? for help): n
Partition number (1-128, default 1): 
First sector (34-1953525134, default = 2048) or {+-}size{KMGTP}: 
Last sector (2048-1953525134, default = 1953525134) or {+-}size{KMGTP}: 
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300): 
Changed type of partition to 'Linux filesystem'

Command (? for help): w

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!

Do you want to proceed? (Y/N): y
OK; writing new GUID partition table (GPT) to /dev/sda.
The operation has completed successfully.
</code>

Kontrola:

**~$ lsblk**
<code>
NAME                 MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda                    8:0    0 931,5G  0 disk  
└─sda1                 8:1    0 931,5G  0 part  
</code>

**~$ sudo gdisk -l /dev/sda**
<code>
GPT fdisk (gdisk) version 1.0.3

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.
Disk /dev/sda: 1953525168 sectors, 931.5 GiB
Model: HD650           
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): 684CCBB4-EEA4-4C92-BC2A-6D16D1B0ADF8
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 1953525134
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048      1953525134   931.5 GiB   8300  Linux filesystem
</code>

**~$ sudo cryptsetup luksFormat /dev/sda1** 

<code>
WARNING!
========
Toto nevratně přepíše data na /dev/sda1.

Are you sure? (Type uppercase yes): YES
Zadejte heslo pro /dev/sda1: 
Ověřte heslo: 
</code>

**~$ sudo cryptsetup -v luksOpen /dev/sda1 red**
<code>
Zadejte heslo pro /dev/sda1: 
Pozice klíče 0 odemknuta.
Příkaz úspěšně vykonán.
</code>

**~$ lsblk**
<code>
NAME                 MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda                    8:0    0 931,5G  0 disk  
└─sda1                 8:1    0 931,5G  0 part  
  └─red              254:3    0 931,5G  0 crypt 
</code>

**~$ sudo mkfs.ext4 /dev/mapper/red**
<code>
mke2fs 1.44.5 (15-Dec-2018)
Creating filesystem with 244186289 4k blocks and 61046784 inodes
Filesystem UUID: eecd9db7-a672-43e5-b286-335766bedf88
Superblock backups stored on blocks: 
	32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
	4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 
	102400000, 214990848

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (262144 blocks): done
Writing superblocks and filesystem accounting information: done
</code>

**~$ sudo mkdir /mnt/RED**

**~$ sudo mount /dev/mapper/red /mnt/RED**

**~$ lsblk**
<code>
NAME                 MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda                    8:0    0 931,5G  0 disk  
└─sda1                 8:1    0 931,5G  0 part  
  └─red              254:3    0 931,5G  0 crypt /mnt/RED
</code>

**~$ mount | grep -i red**
<code>
/dev/mapper/red on /mnt/RED type ext4 (rw,relatime)
</code>

Občas se stane, že napoprvé se oddíl přimountuje jako ro (read-only), stačí jej odpojit a připojit znovu (umount ... / mount ...).

FIXME 
  * luksClose
  * záloha LUKS hlavičky