Error:
POlease unlock disk sda3_crypt:
/run/lvm/lvmetad.socket: connect failed: no such file or directory
WARNING: Failed to connect to lvmedtad. Falling back to internal scanning
Reading all physical volumes. This may take a while...
Found volume group "ubuntu-vg" using metadata type lvm3
/run/lvm/lvmetad.socket: connect failed: No such file or directory:
WARNING: Failed to connect to lvmetad: Falling back to internal scanning
2 logical volume(s) in volume group "ubuntu-vg" now active
cryptsetup: sda3_crypt set up successfully

BLKID

/dev/mapper/sda3_crypt: UUID="AxnSOa-5kc0-9HYP-K391-wWNF-Mumx-nKl7vt" TYPE="LVM2_member"
/dev/mapper/ubuntu--vg-root: UUID="2689f39a-0095-448b-94f8-3e054b593db8" TYPE="ext4"
/dev/sda1: UUID="683D-1569" TYPE="vfat" PARTUUID="66d02fa1-f4d5-46a9-96b1-1460b221ef64"
/dev/sda2: UUID="be54690b-6d0d-4a3f-98d9-b447ed6d3c5f" TYPE="ext2" PARTUUID="8e7f236f-0697-48cb-aca5-e72aefb38b19"
/dev/sda3: UUID="76093536-fec2-412d-8c0a-2f71b02f8f16" TYPE="crypto_LUKS" PARTUUID="04916347-fc31-4128-bd0f-5b394906ee32"
/dev/sdb1: LABEL="WD Green 2TB" UUID="BE76DD0B76DCC4F5" TYPE="ntfs" PARTUUID="bef243fc-01"
/dev/sdc1: LABEL="My Book" UUID="C6B04293B0428A3F" TYPE="ntfs" PARTUUID="00021365-01"
/dev/sdd1: LABEL="Seagate 4TB" UUID="26AAB369AAB333E1" TYPE="ntfs"
/dev/sde1: UUID="1f76a3bd-2766-43fd-9e6e-58011bfcc973" TYPE="crypto_LUKS" PARTUUID="febce139-01"
/dev/mapper/backup: LABEL="Backup" UUID="3fe17b39-8aa4-49c7-be59-6be384caa329" TYPE="ext4"

crypttab
sda3_crypt UUID=76093536-fec2-412d-8c0a-2f71b02f8f16 none luks,discard
#cryptswap1 UUID=44317b62-1887-493e-b131-5817697f6191 /dev/urandom swap,cipher=aes-cbc-essiv:sha256
backup UUID=1f76a3bd-2766-43fd-9e6e-58011bfcc973 /root/keyfile luks

fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
/dev/mapper/ubuntu--vg-root /               ext4    errors=remount-ro 0       1
# /boot was on /dev/sda2 during installation
UUID=be54690b-6d0d-4a3f-98d9-b447ed6d3c5f /boot           ext2    defaults        0       2
# /boot/efi was on /dev/sda1 during installation
UUID=683D-1569  /boot/efi       vfat    defaults        0       1
#/dev/mapper/ubuntu--vg-swap_1 none            swap    sw              0       0
#/dev/mapper/cryptswap1 none swap sw 0 0
/mnt/8704MiB.swap none swap sw 0 0
#LUKS Backup
/dev/mapper/backup /media/backup ext4 defaults 0 0
#NTFS Internal
UUID=BE76DD0B76DCC4F5 /media/WDGreen2tb ntfs-3g defaults,user,locale=en_US.utf8 0 0
#NTFS Removable Disks
UUID=26AAB369AAB333E1 /media/Seagate4tb ntfs-3g defaults,user,locale=en_US.utf8 0 0
UUID=C6B04293B0428A3F /media/WDBook2tb ntfs-3g defaults,user,locale=en_US.utf8 0 0