Build/format/mount encrypted LVM volume
cryptsetup -y -v luksFormat /dev/sdc1 cryptsetup luksOpen /dev/sdc1 encrypted-sdc1 pvcreate /dev/mapper/encrypted-sdc1 vgcreate MAIN /dev/mapper/encrypted-sdc1 lvcreate -n LVMAIN -l 100%FREE MAIN mkfs.ext4 /dev/MAIN/LVMAIN mount /dev/MAIN/LVMAIN /mnt/lvmtest
Build expansion volume
cryptsetup -y -v luksFormat /dev/sdc2 cryptsetup luksOpen /dev/sdc2 encrypted-sdc2 pvcreate /dev/mapper/encrypted-sdc2
Extend the volumegroup and Logical Volume
vgextend MAIN /dev/mapper/encrypted-sdc2 vgdisplay (and look for the free PE's) lvextend -l +1830 /dev/MAIN/LVMAIN
(Online) grow the filesystem
resize2fs /dev/MAIN/LVMAIN
Shutdown procedure
umount /mnt/lvmtest vgchange -an MAIN cryptsetup luksClose /dev/mapper/encrypted-sdc2 cryptsetup luksClose /dev/mapper/encrypted-sdc1
Start again
cryptsetup luksOpen /dev/sdc1 encrypted-sdc1 cryptsetup luksOpen /dev/sdc2 encrypted-sdc2 vgscan --mknodes vgchange -ay mount /dev/MAIN/LVMAIN /mnt/lvmtest