Create a SBD partition for HAE (High Availability) and XML example

- How to configure Stonith/SDB resource

Documentation:

[SBD Fencing]
[SLES Stonith]

1- identify which empty device/partition you have shared among your HA nodes (e.g.; /dev/sbd1). Please, make sure that device/partition is NOT in use before proceeding.

2- Then, run the following command to create the sbd info in /dev/sdb1

sbd -d /dev/sdb1 create

3- check if you have the following info in /dev/sdb1

sbd -d /dev/sdb1 dump
Header version     : 2
Number of slots    : 255
Sector size        : 512
Timeout (watchdog) : 5
Timeout (allocate) : 2
Timeout (loop)     : 1
Timeout (msgwait)  : 10

4- Setup the software watchdog add the line to /etc/init.d/boot.local:

modprobe softdog  

NOTE3: this needs to be done on all nodes.

5- Start the sbd daemon add the following to /etc/sysconfig/sbd:

Note: You may need to create the sbd file.

SBD_DEVICE="/dev/sdb1"
SBD_OPTS="-W"

NOTE4: you need to change the device name for the one you are going to use there. In the case where multipath is being used in conjunction with SBD you can point it to your /dev/mapper/ device or /dev/disk/by-id/.

Now scp the sbd file to all nodes and make sure you put that sbd file under /etc/sysconfig directory.

scp /etc/sysconfig/sbd root@host:/etc/sysconfig/sbd

6- Test the sbd daemon

sbd -d /dev/sdb1 list

The above list command will dump the node slots, and their current messages, from the sbd device. You should see all cluster nodes being listed there; most likely with a message clear.

7- You can now try sending a test message to one of the nodes:

sbd -d /dev/sdb1 message nodea test

The node will acknowledge the receipt of the message in the system logs:

Aug 29 14:10:00 nodea sbd: [13412]: info: Received command test from nodeb

8- Configure the fencing resource Add a STONITH resource of type external/sbd to the CIB, setting the sbd_device instance attribute accordingly.

More details about SBD stonith device at https://wiki.clusterlabs.org/wiki/Using_SBD_with_Pacemaker