2017-04-24 14:37 GMT+02:00, Andreas Klauer <Andreas.Klauer@xxxxxxxxxxxxxx>: > On Mon, Apr 24, 2017 at 02:13:24PM +0200, Patrik Dahlström wrote: >> I'm afraid it doesn't say that. > > You said you found an ext header in the raw data. Yes, I found ext headers in both /dev/sda and /dev/sdf, but it doesn't show up in the 6 disk raid (/dev/md1). > > If that exists then only thing I can think of is that you ended > up picking the wrong offset (or disk order) after all. What offset are you referring to here? The --data-offset to the mdadm --create command? > >> I do know that both raids contains only zeros for >> many MB before any data appears. > > This could be normal for the 5disk array since that part already > reshaped and the offset changed and there just could happen to > be zeroes somewhere in the beginning of a filesystem after the > first block of metadata. Makes sense > > Basically the 5disk array is supposed to have bogus data at > the start in your case. But it should turn into valid data > at whatever point the reshape did not yet reach. Should I then be able to find a copy of ext4 superblock in the 5 disk array once valid data start to appear? > > This bogus data makes it hard to determine the correct offset > but according to the output you showed before the offset should > be 128M here. I found out that there existed a ext4 file system at offset 0x7B80000 (123,5 MB) on both /dev/sda and /dev/sdb. I will adjust my mdadm --create commands to this offset when I get home and try again. > > For the 6disk array you should see valid data (starting with > the filesystem header) for however far the reshape was already done. > Depending on how the filesystem works you might even be able to > mount it but everything that is located behind the progress point > would appear corrupted. Interesting. Like I said above, I will retry the create commands with 123.5 MB --data-offset. > > Again if one of the disks actually was kicked from the array > while the grow was going on, you should leave that disk out as missing > as otherwise it will just appear as wrong data in both arrays. I don't think the disk was ever kicked out. The kernel reset the link and continued, I believe. > > Regards > Andreas Klauer > Best regards Patrik Dahlström -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
