Re: `grub-install` failed on a partitionless fully luks encrypted 4TB HDD

[Andrei Borzenkov]

On Fri, Dec 9, 2016 at 1:45 PM, Hamid Nassiby <address@hidden> wrote:
> As the subject says and I've mentioned in my first post, this disk is
> partitionless. Anyway, there are people who successfully installed grub on
> partitionless disks. For example please take a look at the following links:
>
> grub on partitionless full disk LVM:
>
> http://www.mailbrowse.com/gnu-help-grub/comments-758.html
>

Requires relatively modern LVM2 to reserve space for bootloader in PV,
but yes, this is possible and may be supported.

> Grub on a whole ext4 partitionlesss disk:
>
> http://unix.stackexchange.com/questions/5162/how-to-install-grub-to-a-whole-ext4-disk-without-partition-table
>
> Install grub on a partitionless disk (Arch wiki):
>
> https://wiki.archlinux.org/index.php/GRUB#Install_to_partition_or_partitionless_disk
>

Both embed in filesystem that reserves the first block for jump boot sector.

> grub on a partitionless btrfs disk:
>
> https://wiki.archlinux.org/index.php/Btrfs#Partitionless_Btrfs_disk
>

Come on, really, btrfs explicitly reserves space for bootloader use.

> Therefore lack of a partition table by itself could not be the root of
> problem, but not having enough space for grub installation!

Where did I say something different?

> So before
> solving the problem by eliminating the problem scenario, and regarding the
> successful similar experiences mentioned above,

I do not see "LUKS" or "encrypted" anywhere above.

> I would like to get assured
> about the required space for grub installation at the disk beginning, before
> luks header.

LUKS header starts at the beginning of container, there is no space
"before" LUKS header.

> I have asked Milan Broz about this, waiting for his reply.
>
> Please let me know more about your idea,
>
> Regards,
> Hamid
>
>
> On Fri, Dec 9, 2016 at 11:06 AM, Andrei Borzenkov <address@hidden>
> wrote:
>>
>> On Fri, Dec 9, 2016 at 9:52 AM, Hamid Nassiby <address@hidden> wrote:
>> > Hi Andrei,
>> >
>> > The output of "fdisk -l /dev/sdb":
>> >
>> >> Disk /dev/sdb: 3.7 TiB, 4000787030016 bytes, 7814037168 sectors
>> >> Units: sectors of 1 * 512 = 512 bytes
>> >> Sector size (logical/physical): 512 bytes / 4096 bytes
>> >> I/O size (minimum/optimal): 4096 bytes / 4096 bytes
>> >>
>> >
>> > The output of "blkid":
>> >
>> >> /dev/mapper/wallet: UUID="$Luks" TYPE="LVM2_member"
>> >> /dev/mapper/my_vg-root: LABEL="root" UUID="$root" UUID_SUB="$root_sub"
>> >> TYPE="btrfs"
>> >> /dev/sdb: UUID="$sdb" TYPE="crypto_LUKS"
>>
>> There is no place to install bootloader on this disk. Create partition
>> to use as encrypted container, then you will be able to install
>> bootloader. As you have 4TB disk, you need GPT, so you should
>> additionally create BIOS boot partition where bootloader will be
>> installed.
>
>