Setup DRBD with 3 server (master/slave)

Question

I currently work with pacemaker DRBD setup. I have 3 Debian 9 server and I want to synchronize drive with all server. unfortunately I get error while installing DRBD to my server.

drbd configuration

global { usage-count no; }
common { protocol C;}
resource r0 {
        on oreo {
                device /dev/drbd0;
                disk /dev/sda3;
                address 10.xxx.xxx.205:7788;
                meta-disk internal;
                }
        on cupcone  {
                device /dev/drbd0;
                disk /dev/sda3;
                address 10.xxx.xxx.206:7788;
                meta-disk internal;
                }
        on twinkie  {
                device /dev/drbd0;
                disk /dev/sda3;
                address 10.xxx.xxx.207:7788;
                meta-disk internal;
                }


        }

Step I followed

root@oreo:~# sudo modprobe drbd
root@oreo:~# sudo drbdadm create-md r0
You want me to create a v08 style flexible-size internal meta data block.
There appears to be a v08 flexible-size internal meta data block
already in place on /dev/sda3 at byte offset 6291453898752

Do you really want to overwrite the existing meta-data?
[need to type 'yes' to confirm] yes

initializing activity log
NOT initializing bitmap
Writing meta data...
New drbd meta data block successfully created.

Error I get

root@oreo:~# sudo drbdadm up r0
/etc/drbd.conf:3: in resource r0:
        There are multiple host sections for the peer node.
        Use the --peer option to select which peer section to use.
resource r0: cannot configure network without knowing my peer.

I think error is config file, I don't know how to fix this

please help me

Answer 1

DRBD 8.4.x only supports two nodes. To configure a 3 node or larger DRBD cluster you will need to use DRBD 9 or newer.

Upgrading from DRBD 8.4 to DRBD 9 is covered in the DRBD v9 User's Guide here: https://www.linbit.com/drbd-user-guide/drbd-guide-9_0-en/#s-upgrading-drbd