Re: RAID array is gone, please help

[Stephen Mueller]

OK, I used gdisk to remove the GPT and MBR from each disk.
mdadm --assemble still doesn't work... says it can't find the
superblock. The mdadm --examine commands also say that no
superblock is detected.

I guess I'll go ahead with --create...


On 3/23/2017 20:59, Lennart Sorensen wrote:
> On Thu, Mar 23, 2017 at 08:38:08PM +0100, Stephen Mueller wrote:
> > Apologies, I should have started this on linux-raid...
> >
> >
> > stephen@fred> sudo gdisk -l /dev/sdc
> > GPT fdisk (gdisk) version 1.0.1
> >
> > Partition table scan:
> >   MBR: protective
> >   BSD: not present
> >   APM: not present
> >   GPT: present
> >
> > Found valid GPT with protective MBR; using GPT.
> > Disk /dev/sdc: 7814037168 sectors, 3.6 TiB
> > Logical sector size: 512 bytes
> > Disk identifier (GUID): 60F1D54C-9D17-4688-BD6E-447F5E7408EB
> > Partition table holds up to 128 entries
> > First usable sector is 34, last usable sector is 7814037134
> > Partitions will be aligned on 2048-sector boundaries
> > Total free space is 7814037101 sectors (3.6 TiB)
> >
> > Number  Start (sector)    End (sector)  Size       Code  Name
> > stephen@fred>
> >
> > The other disks are all similar.
> >
> > How do I remove the MBR/GPT tables? So you would do that, and then the
> > mdadm --create?
>
> Well at least that seems to confirm that something restored the GPT from
> the second copy at the end of the disk, wiping out the md superblock
> at 4k.
>
> If you run gdisk /dev/sdc, it has a 'zap' option using the z key to
> delete all traces of GPT.  That ought to do what you want.