[dm-crypt] LUKS is written to a device with no partition table. Is it possible to add a partition table?
joehillen at gmail.com
Tue Apr 19 21:08:37 CEST 2016
I posted this to https://gitlab.com/cryptsetup/cryptsetup/issues/292
but now I'm worried that might not be the appropriate place to ask
I have a 12TB hardware RAID5 external hard drive array.
I had initially planned to only ever encrypt data to the device, but now I
need about half encrypted and half not.
The device is `/dev/sdd`. It mounts as `fatty`.
There is no partition table.
# dd if=/dev/sdd | hexdump -C | head -1
00000000 4c 55 4b 53 ba be 00 01 61 65 73 00 00 00 00 00
# parted /dev/sdd
GNU Parted 3.2
Welcome to GNU Parted! Type 'help' to view a list of commands.
Error: /dev/sdd: unrecognised disk label
Model: ORICO H/ W RAID5 (scsi)
Disk /dev/sdd: 12.0TB
Sector size (logical/physical): 512B/4096B
Partition Table: unknown
As you can see LUKS starts at the first byte of the device.
There is a btrfs filesystem on the LUKS device and I resized it down to 4TB.
# cryptsetup status fatty
/dev/mapper/fatty is active.
keysize: 256 bits
offset: 4096 sectors
size: 23441764352 sectors
# btrfs filesystem show /dev/mapper/fatty
Label: 'fatty' uuid: XXX-XX-XX-XX-XXXXXXXXX
Total devices 1 FS bytes used 2.75TiB
devid 1 size 4.00TiB used 2.80TiB path /dev/mapper/fatty
I can't really move the data anywhere, because it's too big and would
require buying more hardware.
Is it possible to add a partition table without losing the data?
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