Saturday, July 01, 2023

Re: encrypted_hdd_data_recovery(OpenBSD_7.3)

On 6/30/23 08:30, soko.tica wrote:
> Thanks NIck,
>
> How do I exactly try to unlock the disk with bioctl command?
>
> I do not have the appropriate disk to try to rebuild it.
>
> I am trying it from openbsd 6.9 bootable usb. The encrypted hdd was 7.3.

don't do that.
I'm not aware of any incompatibilities between 7.3 and 6.9, but I'm not
going to look, it just isn't a good idea. Bring your 6.9 box up to 7.3,
then do it.


But ... after you upgrade your recovery machine to 7.3, let's assume
your drive you are after is sd2, and the encrypted drive is partition d
(note there are two assumptions there, hopefully my example is wrong,
and you have to understand what I'm suggesting here before blindly
doing it!) :

# bioctl -c C -l /dev/sd2d softraid0

at that point, it will prompt you for your passphrase, and if you enter
that correctly and the disk is intact, it will create a new "drive",
which will have its own disklabel, and you can mount those partitions.

Nick.

>
> Please.
>
> Thanks in advance
>
>
> On Sat, Jun 17, 2023 at 4:33 PM Nick Holland <nick@holland-consulting.net>
> wrote:
>
>> On 6/17/23 08:40, soko.tica wrote:
>> > Hello list,
>> >
>> > I have managed to screw by
>> > #fsck_ffs /dev/sd1a
>> >
>> > the root partition of my unmounted HDD (OpenBSD 7.3 stable, possibly not
>> > fully updated). It crashed during boot due to the power outage, than it
>> was
>> > unable to boot and required fsck_ffs, and I answered 'F' to the 'Fyn'
>> > prompt.
>> >
>> > Here is the present status of it (it is sd0 in this sequence).
>> > ===
>> > Script started on Sat Jun 17 12:26:43 2023
>> > think# disklabel sd0
>> >
>> > # /dev/rsd0c:
>> > type: SCSI
>> > disk: SCSI disk
>> > label: HGST HTS725050A7
>> > duid: 35e70751b7e36f98
>> > flags:
>> > bytes/sector: 512
>> > sectors/track: 63
>> > tracks/cylinder: 255
>> > sectors/cylinder: 16065
>> > cylinders: 60801
>> > total sectors: 976773168
>> > boundstart: 64
>> > boundend: 976768065
>> > drivedata: 0
>> >
>> > 16 partitions:
>> > # size offset fstype [fsize bsize cpg]
>> > a: 976768001 64 RAID
>> > c: 976773168 0 unused
>> > think# ^D
>> >
>> >
>> > Script done on Sat Jun 17 12:26:54 2023
>> > ===
>>
>> this is as I'd expect. but you aren't showing what happens
>> when you try to unlock it I understand you have a problem,
>> but you haven't told us what it is.

I was corrected off-list here. You told us the problem, the
problem is "no backup"

>>
>> If you have a problem when unlocking the disk with the bioctl
>> command, you probably aren't going to get your data back.
>>
>> If you can get the drive unlocked and available as another
>> logical drive, you will probably have to fsck each partition
>> within it. Hopefully any horrible problems here would be
>> contained to individual partitions, and you can pull data off
>> the rest.
>> ...
>>
>> > Naturally, there is data there, and naturally, I have no backup of it. Of
>> > course I do know the passphrase, it is my hdd.
>>
>> this is what we call a learning experience.
>>
>> > If there is any chance to recover it, please let me know.
>>
>> chance, maybe. But almost by design, encrypted storage is more
>> fragile than unencrypted storage.
>>
>> Nick.
>>
>>

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