Comment 24 for bug 1776626

Verified with systemd/237-3ubuntu10.31:

ubuntu@ubuntu-Standard-PC-i440FX-PIIX-1996:~$ sudo vi /etc/crypttab
ubuntu@ubuntu-Standard-PC-i440FX-PIIX-1996:~$ sudo systemctl daemon-reload
ubuntu@ubuntu-Standard-PC-i440FX-PIIX-1996:~$ sudo service systemd-cryptsetup@vdb_crypt start
Please enter passphrase for disk vdb_crypt! ****
ubuntu@ubuntu-Standard-PC-i440FX-PIIX-1996:~$ cat /etc/crypttab
vdb_crypt /dev/vdb none luks,sector-size=4096

ubuntu@ubuntu-Standard-PC-i440FX-PIIX-1996:~$ sudo service systemd-cryptsetup@vdb_crypt status
● systemd-cryptsetup@vdb_crypt.service - Cryptography Setup for vdb_crypt
   Loaded: loaded (/etc/crypttab; generated)
   Active: active (exited) since Tue 2019-10-08 21:05:11 CEST; 13s ago
     Docs: man:crypttab(5)
           man:systemd-cryptsetup-generator(8)
           man:systemd-cryptsetup@.service(8)
  Process: 1999 ExecStart=/lib/systemd/systemd-cryptsetup attach vdb_crypt /dev/vdb none luks,sector-size=4096 (cod
 Main PID: 1999 (code=exited, status=0/SUCCESS)

okt 08 21:05:06 ubuntu-Standard-PC-i440FX-PIIX-1996 systemd[1]: Starting Cryptography Setup for vdb_crypt...
okt 08 21:05:09 ubuntu-Standard-PC-i440FX-PIIX-1996 systemd-cryptsetup[1999]: Set cipher aes, mode xts-plain64, key
okt 08 21:05:11 ubuntu-Standard-PC-i440FX-PIIX-1996 systemd[1]: Started Cryptography Setup for vdb_crypt.
ubuntu@ubuntu-Standard-PC-i440FX-PIIX-1996:~$ sudo fdisk /dev/mapper/vdb_crypt

Welcome to fdisk (util-linux 2.31.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0x313e0336.

Command (m for help): p
Disk /dev/mapper/vdb_crypt: 5 GiB, 5366611968 bytes, 1310208 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x313e0336

Command (m for help): q

ubuntu@ubuntu-Standard-PC-i440FX-PIIX-1996:~$