[DRBD-user] DRBD 9: 3-node mirror error (Low.dev. smaller than requested DRBD-dev. size.)

[Paul Clements]

> The problem is that the new meta data for three nodes is larger than the
> old meta data for two nodes, therefore the sum of meta data and user
> data would be larger than the size of the device.
> You will have to either reduce the size of the filesystem, so that the
> new meta data fits in at the end of the device, or increase the size of
> the device.

Sorry, I must be missing something, but I erased the entire device
(i.e., dd if=/dev/zero of=/dev/dm-0), metadata, filesystem and all on
all 3 nodes. How can this still be the problem?

This is exactly what I did, on all three nodes:

# dd if=/dev/zero of=/dev/dm-0 bs=128k
dd: error writing '/dev/dm-0': No space left on device

573697+0 records in
573696+0 records out
75195482112 bytes (75 GB) copied, 160.872 s, 467 MB/s

[root at sios0 ~]# drbdadm create-md r0
initializing activity log
initializing bitmap (4484 KB) to all zero
Writing meta data...
New drbd meta data block successfully created.
success

[root at sios0 ~]# drbdadm up r0
0: Failure: (111) Low.dev. smaller than requested DRBD-dev. size.
Command 'drbdsetup attach 0 /dev/dm-0 /dev/dm-0 internal' terminated
with exit code 10


I even did "drbdadm wipe-md r0" in addition to the above, just to be sure.

Is there some other option I need to specify for three nodes?

Thanks,
Paul