Since OCFS2 is a shared cluster file system expecting concurrent read/write storage access from all cluster nodes, any DRBD resource to be used for storing a OCFS2 filesystem must be configured in dual-primary mode. Also, it is recommended to use some of DRBD’s features for automatic recovery from split brain. And, it is necessary for the resource to switch to the primary role immediately after startup. To do all this, include the following lines in the resource configuration:
resource <resource> { startup { become-primary-on both; ... } net { # allow-two-primaries yes; after-sb-0pri discard-zero-changes; after-sb-1pri discard-secondary; after-sb-2pri disconnect; ... } ... }
![]() | Warning |
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By configuring auto-recovery policies, you are configuring effectively configuring automatic data-loss! Be sure you understand the implications. |
It is not recommended to set the allow-two-primaries
option to yes
upon initial configuration. You should do so after the initial
resource synchronization has completed.
Once you have added these options to your freshly-configured resource, you may initialize your resource as you normally would. After you set the
allow-two-primaries
option to yes
for this
resource, you will be able to promote the resourceto the primary role on both nodes.