[DRBD-user] required external meta-data size change?

[Admin]

Hi all

On 2.6.17.3 amd64 (kernel and userland) + drbd 0.7.20 SVN (as of 14/July) when 
I try to configure external metadata it fails with

ioctl(,SET_DISK_CONFIG,) failed: Invalid argument
Meta device too small.

until I increase the size of the partition containing the metadata to 134MB (I 
thought 128MB was what was required?)

the underlying device is /dev/md_d0 (partitionable software raid) with a gpt 
disk label

drbd.conf:
resource disk0 {
  protocol C;
  startup {
    wfc-timeout  10;
    degr-wfc-timeout 120;    # 2 minutes.
  }
  disk {
    on-io-error   detach;
  }
  net {
  }
  syncer {
    rate 50M;
    group 1;
    al-extents 257;
  }
  on node-1 {
    device     /dev/drbd0;
    disk       /dev/md_d0p3;
    address    192.168.2.1:7788;
    meta-disk  /dev/md_d0p1[0];
  }

  on node-2 {
    device    /dev/drbd0;
    disk      /dev/md_d0p3;
    address   192.168.2.2:7788;
    meta-disk /dev/md_d0p1[0];
  }
}
resource disk1 {
  protocol C;
  startup {
    wfc-timeout  10;
    degr-wfc-timeout 120;    # 2 minutes.
  }
  disk {
    on-io-error   detach;
  }
  net {
  }
  syncer {
    rate 50M;
    group 1;
    al-extents 257;
  }
  on node-1 {
    device     /dev/drbd1;
    disk       /dev/md_d0p4;
    address    192.168.2.1:7789;
    meta-disk  /dev/md_d0p2[0];
  }

  on node-2 {
    device    /dev/drbd1;
    disk      /dev/md_d0p4;
    address   192.168.2.2:7789;
    meta-disk /dev/md_d0p2[0];
  }
}

# Commands used in creating the partitions
# md_d0p1 is told to start at 1MB because gpt table takes the first 16k of the
# disk and I want to align filesystems with raid stripes.
/etc/init.d/drbd stop
/etc/init.d/drbd zap
parted -s /dev/md_d0 mklabel gpt
parted -s /dev/md_d0 mkpart primary 1 135
parted -s /dev/md_d0 mkpart primary 135 270
parted -s /dev/md_d0 mkpart primary 270 70G
parted -s -- /dev/md_d0 mkpart primary 70G -0
dd if=/dev/zero of=/dev/md_d0p1
dd if=/dev/zero of=/dev/md_d0p2
/etc/init.d/drbd start

If I drop the size of either of the metadata partitions (md_d0p1 or md_d0p2) 
then the 'Meta device too small.' error occurs

Is this variation from the documentation something I should be concerned with?

Admin