Re: should btrfsck fix a bad superblock?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, Dec 28, 2015 at 7:28 PM, Duncan <1i5t5.duncan@xxxxxxx> wrote:
> Chris Murphy posted on Mon, 28 Dec 2015 17:10:14 -0700 as excerpted:
>
>> Hi,
>>
>> I (intentionally) used wipefs -a on a device with a btrfs. As expected
>> btrfs check doesn't recognize the device as having a btrfs volume
>> anymore.
>>
>> Slightly surprising that it doesn't mention other intact supers are
>> found.
>>
>> Most surprising that options -s1 --repair doesn't fix it.
>>
>> I thought maybe it's intentional, only with explicitly bad magic, and
>> I'd get different results if it were zero'd. So I zero'd it and I get
>> the same results. s0 superblock isn't repaired with --repair.
>>
>> Bug?
>>
>> Of course I can fix it with echo+dd.
>
> Btrfs check's -s option simply lets you use a different superblock.  I
> don't believe check is designed to actually fix superblocks, tho I guess
> with --repair it fixes certain bad fields in them.
>
> What you want to actually recover bad superblocks from good copies is
> btrfs rescue super-recover.

Yep! I forgot about that. But it's still confusing that particular
repair is split out.



-- 
Chris Murphy
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Filesystem Development]     [Linux NFS]     [Linux NILFS]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux