Prior to DRBD 8.4, changes to the replication protocol were impossible
while the resource was on-line and active. You would have to change
the protocol
option in your resource configuration file, then issue
drbdadm disconnect
and finally drbdadm connect
on both nodes.
In DRBD 8.4, the replication protocol can be changed on the fly. You may, for example, temporarily switch a connection to asynchronous replication from its normal, synchronous replication mode.
Changing replication protocol while connection is established.
drbdadm net-options --protocol=A <resource>
Prior to DRBD 8.4, it was impossible to switch between single-Primary
to dual-Primary or back while the resource was on-line and active. You
would have to change the allow-two-primaries
option in your resource
configuration file, then issue drbdadm disconnect
and finally
drbdadm connect
on both nodes.
In DRBD 8.4, it is possible to switch modes on-line.
![]() | Caution |
---|---|
It is required for an application using DRBD dual-Primary mode to use a clustered file system or some other distributed locking mechanism. This applies regardless of whether dual-Primary mode is enabled on a temporary or permanent basis. |
Refer to Section 6.8.2, “Temporary dual-primary mode” for switching to dual-Primary mode while the resource is on-line.