Hi, On 04/19/2016 10:06 PM, Arno Wagner wrote: > First, > > please do not post HTML email to the list. > > Second, while it is possible to add a partition table > without backup, it is an extremely dangerous operation, > dangerous enough that your chances of doing so successfully > are near zero if you have to ask how to do it. I strongly > recommend against trying. > > Now, if you want to lose all data, here is what you can try: > 1. Resize filesystem in LUKS container to half device size. Joe has 2.8/4 TiB in use. I think it only works in-situ which is at least as double as dangerous as your approach :-) > 2. Move LUKS container to end > 3. Create partition table and a partition that covers 1st half > of the device. Create LUKS container and in it a > filesystem in that partition. > 4. Mount LUKS container in 2nd half of disk (using offset) > and LUKS conteiner in partition. > 5. Copy all data from filesystem in LUKS container in 2nd half > of disk to filesystem in LUKS conteiner in 1st half. > 6. Unmap container in 2nd half of disk. > 7. Create 2nd partition covering 2nd half of disk and > put filesystem in there. I second, this sounds a bit safer than my idea. Maybe it is possible to backup 800GiB of data to follow Arnos solution. Ralf > > If you make one tiny mistake anywhere, chances are your > data is gone. Do not try this without full, current backup. > > Regards, > Arno > > > On Tue, Apr 19, 2016 at 21:08:37 CEST, Joe Hillenbrand wrote: >> I posted this to [1]https://gitlab.com/cryptsetup/cryptsetup/issues/292 >> but now I'm worried that might not be the appropriate place to ask >> questions. >> 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 >> |LUKS....aes.....| >>    # parted /dev/sdd >>    GNU Parted 3.2 >>    Using /dev/sdd >>    Welcome to GNU Parted! Type 'help' to view a list of commands. >>    (parted) >> print                                 >>                          >>    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 >>    Disk Flags: >> 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. >>      type:   LUKS1 >>      cipher: aes-xts-plain64 >>      keysize: 256 bits >>      device: /dev/sdd >>      offset: 4096 sectors >>      size:   23441764352 sectors >>      mode:   read/write >>    # 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? >> >> References >> >> 1. https://gitlab.com/cryptsetup/cryptsetup/issues/292 >> _______________________________________________ >> dm-crypt mailing list >> dm-crypt@xxxxxxxx >> http://www.saout.de/mailman/listinfo/dm-crypt > _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
