grub-probe: "found two disks with the index 3 for RAID md2" after changing superblock 0.9 to 1.0

grub-probe: "found two disks with the index 3 for RAID md2" after changing superblock 0.9 to 1.0

[Andy Smith]

Hi,

During the process of shrinking the number of devices in a raid-10
array from 6 down to 4¹, I needed to upgrade the superblock from 0.9
to 1.0.

Now, when I run grub-probe on that host it gives me complaints like
this:

    error: found two disks with the index 3 for RAID md2.
    error: superfluous RAID member (6 found).

(many times over)

Searching around I learn that it may be because grub looks at the
end of the disk and finds an md superblock but cannot tell if it is
for the entire disk or for the final partition on the disk:

    http://savannah.gnu.org/bugs/index.php?34250

In my case, I have four disks sda to sdd all of which have three
partitions on them, and md2 is composed of the third (last)
partition.

    $ cat /proc/mdstat 
    Personalities : [raid1] [raid10] 
    md2 : active raid10 sdd3[0] sdb3[3] sdc3[4] sda3[5]
          618726528 blocks super 1.0 64K chunks 2 near-copies [4/4] [UUUU]

    md1 : active raid10 sda2[0] sdd2[3] sdc2[2] sdb2[1]
          5874688 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]

    md0 : active raid1 sdd1[0] sdc1[3] sdb1[2] sda1[1]
          256896 blocks [4/4] [UUUU]

    unused devices: <none>

The thing is, that bug report is quite old and is marked closed, and
also states:

    "The problem is that 0.9x metadata block doesn't have enough
    info to check it. With 1.x we have no such problem."

Of course, it *is* 1.x superblock. Did the poster actually mean to
say that they have no problem with v1.1 and v1.2 (because they are
located at or near the beginning of the device, not at the end)?

The host is Debian wheezy with grub-pc package version
1.99-27+deb7u2 so if that bug is closed due to a fix, I would expect
to have it by now.

There is also a Debian bug bearing some similarity, and that is also
marked fixed upstream and references the above Gnu bug report.

    https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=620390

The host still boots but that may be because md2 is not involved in
booting anyway.

Do other people experience this?

Is it unavoidable with v1.0 superblock?

If so, is there any way to convert to 1.1 or 1.2 without recreating
the array?

Verbose grub-probe output is appended.

Cheers,
Andy

¹ The thread describing that is here:
  http://marc.info/?l=linux-raid&m=140881268031291&w=2

$ sudo grub-probe --target=fs -v /boot/grub
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd1.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd2.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd3.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd4.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd5.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd6.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd7.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd8.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd9.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd10.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd11.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: scanning hd0 for LVM.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: scanning hd1 for LVM.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: scanning hd2 for LVM.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: scanning hd3 for LVM.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: scanning hd4 for LVM.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: scanning hd5 for LVM.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: scanning hd6 for LVM.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: scanning hd7 for LVM.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: scanning hd8 for LVM.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: scanning hd9 for LVM.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: scanning hd10 for LVM.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: scanning hd11 for LVM.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd4.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd5.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd6.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd7.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd8.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd9.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd10.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd11.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd4.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd5.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd6.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd7.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd8.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd9.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd10.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd11.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0,msdos3.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: Found array md2 (mdraid09).
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0,msdos2.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0,msdos1.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: Found array md0 (mdraid09).
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1,msdos3.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1,msdos2.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1,msdos1.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2,msdos3.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2,msdos2.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2,msdos1.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3,msdos3.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3,msdos2.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3,msdos1.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd4.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd5.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd6.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd7.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd8.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd9.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd10.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: Scanning for mdraid09 RAID devices on disk hd11.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk md0.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0,msdos3.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0,msdos2.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: Found array md/1 (mdraid1x).
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0,msdos1.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1,msdos3.
grub-probe: info: the size of hd1 is 625134827.
error: found two disks with the index 3 for RAID md2.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1,msdos2.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1,msdos1.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2,msdos3.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2,msdos2.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2,msdos1.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3,msdos3.
grub-probe: info: the size of hd3 is 625134827.
error: superfluous RAID member (6 found).
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3,msdos2.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3,msdos1.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd4.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd5.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd6.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd7.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd8.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd9.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd10.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: Scanning for mdraid1x RAID devices on disk hd11.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: scanning md/1 for LVM.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning md0 for LVM.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning md2 for LVM.
grub-probe: info: scanning hd0 for LVM.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: scanning hd0,msdos3 for LVM.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd0,msdos2 for LVM.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd0,msdos1 for LVM.
grub-probe: info: the size of hd0 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd1 for LVM.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: scanning hd1,msdos3 for LVM.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd1,msdos2 for LVM.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd1,msdos1 for LVM.
grub-probe: info: the size of hd1 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd2 for LVM.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: scanning hd2,msdos3 for LVM.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd2,msdos2 for LVM.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd2,msdos1 for LVM.
grub-probe: info: the size of hd2 is 625142448.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd3 for LVM.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: scanning hd3,msdos3 for LVM.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: scanning hd3,msdos2 for LVM.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd3,msdos1 for LVM.
grub-probe: info: the size of hd3 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: scanning hd4 for LVM.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd4 is 625134827.
grub-probe: info: scanning hd5 for LVM.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd5 is 976773168.
grub-probe: info: scanning hd6 for LVM.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd6 is 3907029168.
grub-probe: info: scanning hd7 for LVM.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd7 is 5860533168.
grub-probe: info: scanning hd8 for LVM.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd8 is 3907029168.
grub-probe: info: scanning hd9 for LVM.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd9 is 3907029168.
grub-probe: info: scanning hd10 for LVM.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd10 is 976773168.
grub-probe: info: scanning hd11 for LVM.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: no LVM signature found.
grub-probe: info: the size of hd11 is 5860533168.
grub-probe: info: opening mduuid/78cf4169e31908f4e667021c582159fb.
ext2

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Re: grub-probe: "found two disks with the index 3 for RAID md2" after changing superblock 0.9 to 1.0

[NeilBrown]

[-- Attachment #1: Type: text/plain, Size: 23761 bytes --]

On Mon, 15 Sep 2014 06:47:41 +0000 Andy Smith <andy@strugglers.net> wrote:

> Hi,
> 
> During the process of shrinking the number of devices in a raid-10
> array from 6 down to 4¹, I needed to upgrade the superblock from 0.9
> to 1.0.
> 
> Now, when I run grub-probe on that host it gives me complaints like
> this:
> 
>     error: found two disks with the index 3 for RAID md2.
>     error: superfluous RAID member (6 found).
> 
> (many times over)
> 
> Searching around I learn that it may be because grub looks at the
> end of the disk and finds an md superblock but cannot tell if it is
> for the entire disk or for the final partition on the disk:
> 
>     http://savannah.gnu.org/bugs/index.php?34250
> 
> In my case, I have four disks sda to sdd all of which have three
> partitions on them, and md2 is composed of the third (last)
> partition.

Is this start of that partition (/sys/block/sda3/start) a multiple of 64K
(i.e. a multiple of 128 sectors)?
If it is, and a if a 0.90 superblock is there, that could be the problem.

> 
>     $ cat /proc/mdstat 
>     Personalities : [raid1] [raid10] 
>     md2 : active raid10 sdd3[0] sdb3[3] sdc3[4] sda3[5]
>           618726528 blocks super 1.0 64K chunks 2 near-copies [4/4] [UUUU]
> 
>     md1 : active raid10 sda2[0] sdd2[3] sdc2[2] sdb2[1]
>           5874688 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
> 
>     md0 : active raid1 sdd1[0] sdc1[3] sdb1[2] sda1[1]
>           256896 blocks [4/4] [UUUU]
> 
>     unused devices: <none>
> 
> The thing is, that bug report is quite old and is marked closed, and
> also states:
> 
>     "The problem is that 0.9x metadata block doesn't have enough
>     info to check it. With 1.x we have no such problem."
> 
> Of course, it *is* 1.x superblock. Did the poster actually mean to
> say that they have no problem with v1.1 and v1.2 (because they are
> located at or near the beginning of the device, not at the end)?

0.90 has the problem, 1.x doesn't.
Maybe there is an old 0.90 superblock confusing things.  It lives in a
different location than the others and so there is room for confusion.

  mdadm --examine --metadata=0.90 /dev/sda3

which show you the 0.90 metadata if there is any.

  mdadm --zero-super --metadata=0.90 /dev/sda3

will remove any 0.90 metadata.


NeilBrown


> 
> The host is Debian wheezy with grub-pc package version
> 1.99-27+deb7u2 so if that bug is closed due to a fix, I would expect
> to have it by now.
> 
> There is also a Debian bug bearing some similarity, and that is also
> marked fixed upstream and references the above Gnu bug report.
> 
>     https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=620390
> 
> The host still boots but that may be because md2 is not involved in
> booting anyway.
> 
> Do other people experience this?
> 
> Is it unavoidable with v1.0 superblock?
> 
> If so, is there any way to convert to 1.1 or 1.2 without recreating
> the array?
> 
> Verbose grub-probe output is appended.
> 
> Cheers,
> Andy
> 
> ¹ The thread describing that is here:
>   http://marc.info/?l=linux-raid&m=140881268031291&w=2
> 
> $ sudo grub-probe --target=fs -v /boot/grub
> grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd0.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd1.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd2.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd3.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd4.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd5.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd6.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd7.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd8.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd9.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd10.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: Scanning for dmraid_nv RAID devices on disk hd11.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: scanning hd0 for LVM.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: scanning hd1 for LVM.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: scanning hd2 for LVM.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: scanning hd3 for LVM.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: scanning hd4 for LVM.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: scanning hd5 for LVM.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: scanning hd6 for LVM.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: scanning hd7 for LVM.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: scanning hd8 for LVM.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: scanning hd9 for LVM.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: scanning hd10 for LVM.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: scanning hd11 for LVM.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd4.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd5.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd6.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd7.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd8.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd9.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd10.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd11.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd4.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd5.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd6.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd7.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd8.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd9.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd10.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd11.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0,msdos3.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: Found array md2 (mdraid09).
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0,msdos2.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd0,msdos1.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: Found array md0 (mdraid09).
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1,msdos3.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1,msdos2.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd1,msdos1.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2,msdos3.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2,msdos2.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd2,msdos1.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3,msdos3.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3,msdos2.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd3,msdos1.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd4.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd5.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd6.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd7.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd8.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd9.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd10.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: Scanning for mdraid09 RAID devices on disk hd11.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk md0.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0,msdos3.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0,msdos2.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: Found array md/1 (mdraid1x).
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd0,msdos1.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1,msdos3.
> grub-probe: info: the size of hd1 is 625134827.
> error: found two disks with the index 3 for RAID md2.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1,msdos2.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd1,msdos1.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2,msdos3.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2,msdos2.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd2,msdos1.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3,msdos3.
> grub-probe: info: the size of hd3 is 625134827.
> error: superfluous RAID member (6 found).
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3,msdos2.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd3,msdos1.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd4.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd5.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd6.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd7.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd8.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd9.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd10.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: Scanning for mdraid1x RAID devices on disk hd11.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: scanning md/1 for LVM.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning md0 for LVM.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning md2 for LVM.
> grub-probe: info: scanning hd0 for LVM.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: scanning hd0,msdos3 for LVM.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning hd0,msdos2 for LVM.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning hd0,msdos1 for LVM.
> grub-probe: info: the size of hd0 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning hd1 for LVM.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: scanning hd1,msdos3 for LVM.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning hd1,msdos2 for LVM.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning hd1,msdos1 for LVM.
> grub-probe: info: the size of hd1 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning hd2 for LVM.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: scanning hd2,msdos3 for LVM.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning hd2,msdos2 for LVM.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning hd2,msdos1 for LVM.
> grub-probe: info: the size of hd2 is 625142448.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning hd3 for LVM.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: scanning hd3,msdos3 for LVM.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: scanning hd3,msdos2 for LVM.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning hd3,msdos1 for LVM.
> grub-probe: info: the size of hd3 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: scanning hd4 for LVM.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd4 is 625134827.
> grub-probe: info: scanning hd5 for LVM.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd5 is 976773168.
> grub-probe: info: scanning hd6 for LVM.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd6 is 3907029168.
> grub-probe: info: scanning hd7 for LVM.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd7 is 5860533168.
> grub-probe: info: scanning hd8 for LVM.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd8 is 3907029168.
> grub-probe: info: scanning hd9 for LVM.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd9 is 3907029168.
> grub-probe: info: scanning hd10 for LVM.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd10 is 976773168.
> grub-probe: info: scanning hd11 for LVM.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: no LVM signature found.
> grub-probe: info: the size of hd11 is 5860533168.
> grub-probe: info: opening mduuid/78cf4169e31908f4e667021c582159fb.
> ext2
> 
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> the body of a message to majordomo@vger.kernel.org
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Re: grub-probe: "found two disks with the index 3 for RAID md2" after changing superblock 0.9 to 1.0

[Andy Smith]

Hi Neil,

On Mon, Sep 15, 2014 at 05:00:37PM +1000, NeilBrown wrote:
> On Mon, 15 Sep 2014 06:47:41 +0000 Andy Smith <andy@strugglers.net> wrote:
> > The thing is, that bug report is quite old and is marked closed, and
> > also states:
> > 
> >     "The problem is that 0.9x metadata block doesn't have enough
> >     info to check it. With 1.x we have no such problem."
> > 
> > Of course, it *is* 1.x superblock. Did the poster actually mean to
> > say that they have no problem with v1.1 and v1.2 (because they are
> > located at or near the beginning of the device, not at the end)?
> 
> 0.90 has the problem, 1.x doesn't.

Right.

> Maybe there is an old 0.90 superblock confusing things.  It lives in a
> different location than the others and so there is room for confusion.

I think that must be it.

>   mdadm --examine --metadata=0.90 /dev/sda3
> 
> which show you the 0.90 metadata if there is any.

/dev/sda3:
          Magic : a92b4efc
        Version : 0.90.01
           UUID : 3905b303:ca604b72:be5949c4:ab051b7a
  Creation Time : Sun Jun  4 08:18:58 2006
     Raid Level : raid10
  Used Dev Size : 309363264 (295.03 GiB 316.79 GB)
     Array Size : 928089792 (885.10 GiB 950.36 GB)
   Raid Devices : 6
  Total Devices : 6
Preferred Minor : 2

    Update Time : Sun Aug 24 14:26:50 2014
          State : clean
 Active Devices : 6
Working Devices : 6
 Failed Devices : 0
  Spare Devices : 0
       Checksum : e613d577 - correct
         Events : 312149996

         Layout : near=2
     Chunk Size : 64K

      Number   Major   Minor   RaidDevice State
this     5       8        3        5      active sync   /dev/sda3

   0     0       8       51        0      active sync   /dev/sdd3
   1     1       8       67        1      active sync
   2     2       8       83        2      active sync
   3     3       8       19        3      active sync   /dev/sdb3
   4     4       8       35        4      active sync   /dev/sdc3
   5     5       8        3        5      active sync   /dev/sda3

This shows the array when it had 6 devices as well, so clearly from
before the metadata update and shrink to 4 devices.

>   mdadm --zero-super --metadata=0.90 /dev/sda3
> 
> will remove any 0.90 metadata.

Trying that whole the array is running:

mdadm: Couldn't open /dev/sda3 for write - not zeroing

This needs to be done with the array stopped, presumably?

Thanks for the explanation!

Cheers,
Andy

Re: grub-probe: "found two disks with the index 3 for RAID md2" after changing superblock 0.9 to 1.0

[NeilBrown]

[-- Attachment #1: Type: text/plain, Size: 3084 bytes --]

On Mon, 15 Sep 2014 17:12:52 +0000 Andy Smith <andy@strugglers.net> wrote:

> Hi Neil,
> 
> On Mon, Sep 15, 2014 at 05:00:37PM +1000, NeilBrown wrote:
> > On Mon, 15 Sep 2014 06:47:41 +0000 Andy Smith <andy@strugglers.net> wrote:
> > > The thing is, that bug report is quite old and is marked closed, and
> > > also states:
> > > 
> > >     "The problem is that 0.9x metadata block doesn't have enough
> > >     info to check it. With 1.x we have no such problem."
> > > 
> > > Of course, it *is* 1.x superblock. Did the poster actually mean to
> > > say that they have no problem with v1.1 and v1.2 (because they are
> > > located at or near the beginning of the device, not at the end)?
> > 
> > 0.90 has the problem, 1.x doesn't.
> 
> Right.
> 
> > Maybe there is an old 0.90 superblock confusing things.  It lives in a
> > different location than the others and so there is room for confusion.
> 
> I think that must be it.
> 
> >   mdadm --examine --metadata=0.90 /dev/sda3
> > 
> > which show you the 0.90 metadata if there is any.
> 
> /dev/sda3:
>           Magic : a92b4efc
>         Version : 0.90.01
>            UUID : 3905b303:ca604b72:be5949c4:ab051b7a
>   Creation Time : Sun Jun  4 08:18:58 2006
>      Raid Level : raid10
>   Used Dev Size : 309363264 (295.03 GiB 316.79 GB)
>      Array Size : 928089792 (885.10 GiB 950.36 GB)
>    Raid Devices : 6
>   Total Devices : 6
> Preferred Minor : 2
> 
>     Update Time : Sun Aug 24 14:26:50 2014
>           State : clean
>  Active Devices : 6
> Working Devices : 6
>  Failed Devices : 0
>   Spare Devices : 0
>        Checksum : e613d577 - correct
>          Events : 312149996
> 
>          Layout : near=2
>      Chunk Size : 64K
> 
>       Number   Major   Minor   RaidDevice State
> this     5       8        3        5      active sync   /dev/sda3
> 
>    0     0       8       51        0      active sync   /dev/sdd3
>    1     1       8       67        1      active sync
>    2     2       8       83        2      active sync
>    3     3       8       19        3      active sync   /dev/sdb3
>    4     4       8       35        4      active sync   /dev/sdc3
>    5     5       8        3        5      active sync   /dev/sda3
> 
> This shows the array when it had 6 devices as well, so clearly from
> before the metadata update and shrink to 4 devices.
> 
> >   mdadm --zero-super --metadata=0.90 /dev/sda3
> > 
> > will remove any 0.90 metadata.
> 
> Trying that whole the array is running:
> 
> mdadm: Couldn't open /dev/sda3 for write - not zeroing
> 
> This needs to be done with the array stopped, presumably?

It's preferred, but if you are really confident (and I think you are), then
adding --force is justified and should make it work.

NeilBrown


> 
> Thanks for the explanation!
> 
> Cheers,
> Andy
> --
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html


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Re: grub-probe: "found two disks with the index 3 for RAID md2" after changing superblock 0.9 to 1.0

[Andy Smith]

Hi Neil,

On Tue, Sep 16, 2014 at 07:54:58AM +1000, NeilBrown wrote:
> On Mon, 15 Sep 2014 17:12:52 +0000 Andy Smith <andy@strugglers.net> wrote:
> > On Mon, Sep 15, 2014 at 05:00:37PM +1000, NeilBrown wrote:
> > >   mdadm --zero-super --metadata=0.90 /dev/sda3
> > > 
> > > will remove any 0.90 metadata.
> > 
> > Trying that whole the array is running:
> > 
> > mdadm: Couldn't open /dev/sda3 for write - not zeroing
> > 
> > This needs to be done with the array stopped, presumably?
> 
> It's preferred, but if you are really confident (and I think you are), then
> adding --force is justified and should make it work.

Yep, that worked, thank you! No more complaints from grub-probe.

Do you consider it a bug that mdadm does not zero the old metadata
when upgrading it to a new version?

Or do you consider it a documentation issue to explain that it may
be necessary to manually do it?

I think I would've liked grub-probe at least in verbose mode to say
which version of metadata it was reading from where. That would've
been immediately enlightening, so I'll see if they would accept a
patch for that…

Cheers,
Andy
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Re: grub-probe: "found two disks with the index 3 for RAID md2" after changing superblock 0.9 to 1.0

[NeilBrown]

[-- Attachment #1: Type: text/plain, Size: 1954 bytes --]

On Tue, 16 Sep 2014 04:00:24 +0000 Andy Smith <andy@strugglers.net> wrote:

> Hi Neil,
> 
> On Tue, Sep 16, 2014 at 07:54:58AM +1000, NeilBrown wrote:
> > On Mon, 15 Sep 2014 17:12:52 +0000 Andy Smith <andy@strugglers.net> wrote:
> > > On Mon, Sep 15, 2014 at 05:00:37PM +1000, NeilBrown wrote:
> > > >   mdadm --zero-super --metadata=0.90 /dev/sda3
> > > > 
> > > > will remove any 0.90 metadata.
> > > 
> > > Trying that whole the array is running:
> > > 
> > > mdadm: Couldn't open /dev/sda3 for write - not zeroing
> > > 
> > > This needs to be done with the array stopped, presumably?
> > 
> > It's preferred, but if you are really confident (and I think you are), then
> > adding --force is justified and should make it work.
> 
> Yep, that worked, thank you! No more complaints from grub-probe.
> 
> Do you consider it a bug that mdadm does not zero the old metadata
> when upgrading it to a new version?

No, but it might be excessive caution.  I think it was a deliberate decision
to make it (relatively) easy to revert if anything when wrong.

mdadm always prefers the more recent metadata, so the old metadata is
effectively invisible to mdadm.  Not to grub though.

> 
> Or do you consider it a documentation issue to explain that it may
> be necessary to manually do it?

Maybe.  Though I really don't want to impose that sort of burden on users.
Things should  "just work".  Maybe I should  bite the bullet and just erase
the old metadata.... if I do it *after* the array is assembled it should be
safe.
The code might be a bit clumsy but that isn't the end of the world...

I've made a not on my to-do list :-)

Thanks,
NeilBrown


> 
> I think I would've liked grub-probe at least in verbose mode to say
> which version of metadata it was reading from where. That would've
> been immediately enlightening, so I'll see if they would accept a
> patch for that…
> 
> Cheers,
> Andy


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