Re: multi-device btrfs with single data mode and disk failure

[Alexandre Poux <pums974@gmail.com>]

Le 20/09/2016 à 19:54, Chris Murphy a écrit :
> On Tue, Sep 20, 2016 at 11:03 AM, Alexandre Poux <pums974@gmail.com> wrote:
>
>> If I wanted to try to edit my partitions with an hex editor, where would
>> I find infos on how to do that ?
>> I really don't want to go this way, but if this is relatively simple, it
>> may be worth to try.
> Simple is relative. First you'd need
> https://btrfs.wiki.kernel.org/index.php/On-disk_Format to get some
> understanding of where things are to edit, and then btrfs-map-logical
> to convert btrfs logical addresses to physical device and sector to
> know what to edit.
>
> I'd call it distinctly non-trivial and very tedious.
>
OK, another idea:
would it be possible to trick btrfs with a manufactured file that the
disk is present while it isn't ?

I mean, looking for a few minutes on the hexdump of my trivial test
partition, header of members of btrfs array seems very alike.
So maybe, I can make a file wich would have enough header to make btrfs
believe that this is my device, and then remove it as usual....
looks like a long shot, but it doesn't hurt to ask....