Re: how to recover a corrupted disk

On Wed, Dec 01, 2021 at 01:39:39PM +0530, Sandeep Gupta wrote:
> Hello,
> All partitions except for /dev/rsd1c and /dev/rsd1i are clean.
> For /dev/rsd1c , I get "BAD SUPER BLOCK: MAGIC NUMBER WRONG".
> For /dev/rsd1i, I get "UNEXPECTED INCONSISTENCY".

If that's the case, you are probably done! You could mount
your 'a' partition manually on /mnt, look in /mnt/etc/fstab, and
see which letter partitions belong where; use that info to make
sure you have "found" all your partitions.

BTW, in addition to scan_ffs in base, there is testdisk in ports,
which I think does a better job ATM of finding FFS2 filesystems.

As mentioned, DO NOT do anything with 'c' partition (be glad,
be very glad, that it didn't find anything resembling a superblock
when fsck'ing 'c'!). It's not a mountable partition but a 'wrapper'
for the whole disk.

Re: how to recover a corrupted disk

Sandeep, go ahead reformat your disk.  Do keep in mind the structure of
a BSD disk though

a partition - is usually /

b partition - is usually swap

c partition - is always the entire disk including a, and b,

and it goes on.../var, /usr, /usr/local, /home etc etc

Best Regards,

-peter

On 12/1/21 13:19, Sandeep Gupta wrote:
> Not sure why not. It seems the rsd1c is where the superblock is. Also
> there is no other
> mechanism to refer to the whole disk. I guess it's time to format the disk.
>
> On Wed, Dec 1, 2021 at 4:20 PM Janne Johansson <icepic.dz@gmail.com> wrote:
>> Den ons 1 dec. 2021 kl 11:09 skrev Sandeep Gupta <gupta.sandeep@gmail.com>:
>>> @Peter, @Janne: Thanks for the infos. Newfs seemed promising but it
>>> seems like the disk is beyond repair :(.
>>> I did newfs -N and got quite a few location of superblocks:
>>> Then I tried
>>> fsck_ffs -b #blockid /dev/rsd1c
>> You should *NOT* newfs or fsck against the "C" partition.
>>
>>
>> --
>> May the most significant bit of your life be positive.