[Samba] samba4 + drbd + ctdb + failover

[steve]

Hi
We've got drbd going between 2 nodes:)

ATM there is un-partitioned space on each node but (we think) they are
syncing OK. It looks as though it has synced the whole partition (2GB)
from the primary node 1 to the other node:

node 1
 smb1:/home/steve # cat /proc/drbd
version: 8.4.4 (api:1/proto:86-101)
GIT-hash: 3c1f46cb19993f98b22fdf7e18958c21ad75176d build by SuSE Build
Service

 1: cs:Connected ro:Secondary/Secondary ds:UpToDate/UpToDate C r-----
    ns:2096028 nr:0 dw:0 dr:2096028 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1
wo:f oos:0

node 2
smb2:/home/steve # cat /proc/drbd
version: 8.4.4 (api:1/proto:86-101)
GIT-hash: 3c1f46cb19993f98b22fdf7e18958c21ad75176d build by SuSE Build
Service

 1: cs:Connected ro:Secondary/Secondary ds:UpToDate/UpToDate C r-----
    ns:0 nr:2096028 dw:2096028 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1
wo:f oos:0

Question:
What next?
0. Can any drbd guru give us a thumbs up so far?
1. Is it too late to format the partition(s)?
1. Recommendation for file system to format the partition.
2. Do we need Pacemaker (or something) for the failover or does...
3. ...CTDB do that for us

Thanks,
Steve