From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: on assembly and recovery of a hardware RAID Date: Mon, 20 Mar 2017 16:34:09 +1100 Message-ID: <87lgs0cy0e.fsf@notabene.neil.brown.name> References: <87tw6weubu.fsf@notabene.neil.brown.name> <87d1djdz8y.fsf@notabene.neil.brown.name> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Alfred Matthews Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --=-=-= Content-Type: text/plain On Sat, Mar 18 2017, Alfred Matthews wrote: > I've switched to the backup drives which are clones of the first, now, > so destructive operations are ok if necessary. Also signatures will > have changed. > > 0. Hm. Evidently the system is JHFS instead of HFS+, per the output > below. Unsure if there is separate tooling in Debian. > > 1. Mount via > > mdadm --build /dev/md0 --level=0 -n2 --chunk=512K /dev/sdc2 /dev/sdb2 > > works just fine. Thanks! > > 2. I'm still sticking with the non-destructive, non-mount edits for > now. So I can report the following: > > hpfsck -v /dev/md0 | cat >> hpfsck_output.txt > > yields some stuff probably more enlightening than prior. This is promising until: > *** Checking Backup Volume Header: > Unexpected Volume signature ' ' expected 'H+' Here the backup volume header, which is 2 blocks (blocks are 8K) from the end of the device, looks wrong. This probably means the chunk size is wrong. I would suggest trying different chunksizes, starting at 4K and doubling, until this message goes away. That still might not be the correct chunk size, so I would continue up to several megabytes and find all the chunksizes that seem to work. Then look at what else hpfsck says on those. BTW, this: > Invalid total blocks 2BA8CC68, expected 0 Done *** is not a real problem, just some odd code. NeilBrown --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAljPadEACgkQOeye3VZi gblVohAAnWuOQK8dKS9i9t/k1/3NrLPFNJOPTE+1lUp88+zaT75bq/tGrJmv4bHB T7fspEXAPj3PbyLwF6bAb3dMdA9GFH6riIOvneXgA5EIRrz36Zk2ZijvtWBb6g0n E6L25lYt1pkGZjeYhHj6U6UjpxPsWk0nmZrEkThDIpuRYFMKKQFlneo5XZlWMTjQ RgGpb8dBT3CF0ZuoWg31oeuVzVBTgsT6zRfOc7wETuqJuTY3WF2dMcUgTE0zjhmg kNmDInHWqRQTS815pW6AdYVGOLP+aDx3TmYkczn0+Bzf2Xw0uljMWWlyucv+g3rN 9k5tCj2IOOqcnZKgW5ISA1LGk1gP+Y0VVQBw0H1TdEU+AMhmMRWkI1D+o2ZYaTBz IbKtm0BtpZNvKhcYkvfiuSovpwhfkvgT8UzVT3HYylVZEpLrYoPPhHkzcMrgvuNl M50rRGssZ9dInpg1tAoB52VLnN2oFlo+5vKPcs92p/h/Kh0CGcM/KK4xmgtaiqgI quOCGGlr4Up+VjEyDvxDCIsn63rvhHAvZegLAVdqDCfneYHumFGQ5UBjvsyYzBgl WoJOHuW7Yc1EhsnFW7Nbz6U4eEJ0RAUUG39s+f0UT1juxkAIV25SWt41scK+1q7V Mjlq/bErp49dD9qCTNjygIQniw7HERm5MF7/0ITvRVfewCJ+tOY= =Ri2g -----END PGP SIGNATURE----- --=-=-=--