> -----Original Message----- > From: Aaron Mason <simplersolut...@gmail.com> > Sent: Monday, October 14, 2019 7:13 PM > To: Steven Surdock <ssurd...@engineered-net.com> > Cc: misc@openbsd.org > Subject: Re: Softraid data recovery > > On Tue, Oct 15, 2019 at 7:34 AM Steven Surdock <ssurdock@engineered- > net.com> wrote: > > > > I have a simple RAID1 configuration on wd0, wd1. I was in the process > of performing a rebuild on wd1, as it failed during some heavy reads. > During the rebuild wd0 went into a failure state. After some > troubleshooting I decided to reboot and now my RAID disk, sd1, is > unavailable. Disks wd0 and wd1 don't show any errors, but I have a > replacement disk. I have backups for the critical data and I'd like to > try and recover as much recent data as possible. My thought was to > create a disk image of the "/home/public" data and mount it using > vnconfig, but I seem to be having issues with the appropriate 'dd' > command to do that. > > > > How can I recover as much data as possible off the failed RAID array. > > If I recreate the array, "bioctl -c 1 -l /dev/wd0d,/dev/wd1d > softraid0", will the existing data be preserved? > > > > root@host# disklabel wd0 > > # /dev/rwd0c: > > type: ESDI > > disk: ESDI/IDE disk > > label: WDC WD4001FAEX-0 > > duid: acce36f25df51c8c > > flags: > > bytes/sector: 512 > > sectors/track: 63 > > tracks/cylinder: 255 > > sectors/cylinder: 16065 > > cylinders: 486401 > > total sectors: 7814037168 > > boundstart: 64 > > boundend: 4294961685 > > drivedata: 0 > > > > 16 partitions: > > # size offset fstype [fsize bsize cpg] > > c: 7814037168 0 unused > > d: 7814037104 64 RAID > > > > root@host# more /var/backups/disklabel.sd1.backup # /dev/rsd1c: > > type: SCSI > > disk: SCSI disk > > label: SR RAID 1 > > duid: 8ec2330eabf7cd26 > > flags: > > bytes/sector: 512 > > sectors/track: 63 > > tracks/cylinder: 255 > > sectors/cylinder: 16065 > > cylinders: 486401 > > total sectors: 7814036576 > > boundstart: 64 > > boundend: 7814036576 > > drivedata: 0 > > > > 16 partitions: > > # size offset fstype [fsize bsize cpg] > > a: 2147488704 64 4.2BSD 8192 65536 1 # > /home/public/ > > c: 7814036576 0 unused > > d: 5666547712 2147488768 4.2BSD 8192 65536 1 # > /home/Backups/ > > > > I think at this point you're far better off restoring from backup. > You do have a backup, right? > > As for the disks, ddrescue would be a better option than dd - it'll keep > trying if it encounters another URE whereas dd will up and quit. > Expect it to take several days on disks that big - it's designed to be > gentle to dying disks.
I believe the disks are mostly healthy. In fact I've tried several attempts at dd'ing the data from wd0 with no read issues. It takes about 12 hours to read 1TB. I suspect I'm not aligning sectors properly and the filesystem is not readable. I've tried making an image of /home/public (which is _mostly_ backed up), but fsck doesn't see a reasonable filesystem after I vnconfig the image. So, if anyone has some insight on 'dd if=/dev/wd0d of=public.img bs=512 count=5666547712 skip=xx', it would be great.
