=== current devices ===
<code>
/dev/sda: UUID="6a2e238e-5d22-4a10-b947-01a749c03580" TYPE="crypto_LUKS"
/dev/sdb: UUID="3b0e47f7-bcb4-43d9-a808-cd6e820535bd" TYPE="crypto_LUKS"
/dev/sdc: UUID="1826cea8-4935-488d-9f48-89ca6b7cd448" TYPE="crypto_LUKS"
/dev/sdd: UUID="0bc12478-5fa2-4c14-941b-8d5942d5583f" TYPE="crypto_LUKS"

/dev/mapper/root: UUID="3bbd9b7b-5337-4b78-ae29-fc908a840b92" BLOCK_SIZE="4096" TYPE="reiserfs"
/dev/mapper/all: UUID="djXA83-aY42-wfPV-0I3Z-zKEo-yOWF-2V9o2I" TYPE="LVM2_member"
/dev/mapper/d0b: UUID="c956f779-b0ef-4914-ab24-af18b578d1cc" UUID_SUB="51108d92-ad14-4efd-8b04-9f7461d877e4" BLOCK_SIZE="4096" TYPE="btrfs"
/dev/mapper/d3b: UUID="c956f779-b0ef-4914-ab24-af18b578d1cc" UUID_SUB="c7ad2dbf-3fa8-4a1a-b0db-09a6b856c115" BLOCK_SIZE="4096" TYPE="btrfs"
</code>


=== add a new device ===

<code>
dd if=/dev/urandom of=./d?? bs=1024 count=4
cryptsetup luksFormat -c aes-xts-plain64 -s 512 --key-file /root/keys/d?? /dev/sdX
cryptsetup luksOpen /dev/sdX --key-file /root/keys/d?? d??
btrfs device add /dev/mapper/d?? /mnt/
</code>


=== php config ===