After the DRX Configuration File is created, it is ready to start replication. You can start replication by starting (up) the replication resource with the following commands.
Startup of resources provides a way to start all resources in the configuration file at once with control over the DRX services already prepared during installation or individually through a command-type utility. The following is a description of this
5.1. Service Control
Control of a service depends on the service control commands provided by the OS. The following service control commands were described OS-separated.
5.1.1. Service Startup
c:\>sc start drxsvc
# Centos7 [root@node1 ~]# systemctl start drxsvc # Centos6 [root@node1 ~]# service drxsvc start
5.1.2. Service stop
c:\>sc stop drxsvc
# Centos7 [root@node1 ~]# systemctl stop drxsvc # Centos6 [root@node1 ~]# service drxsvc stop
5.1.3 Watchdog
The DRX Service includes DRX Watchdog for management of the DRX Process. Watchdogs can restart the DRX if it detects an unusual shutdown of the DRX process in the following situations.
- the DRX process ended unexpectedly
- You shut down the DRX using the "drx-ctl shutdown" command.
This restart by Watchdog is permanently recorded in the DRX Log and is left in history.
Because the DRX process is automatically restarted by Watchdog when it terminates under normal circumstances, you must exit the DRX Service Stop to completely terminate the DRX process.
5.2. Resource Control
To control the resource individually, use the up/down command in drx-ctl. you can also start/stop all resources using the 'all' option in drx-ctl.
- Up of drx-ctl and up provided by drbdadm have different functional meanings. The up in drbdadm is the command that prepares the replication target device for the resource and the up in drx-ctl to create a channel that intermediates replication connections.
- The procedure requires drbdadm up after drx-ctl-up to connect to the replication. This is because the connection between drbd and drbd must be attempted after the DRX intermediary channel is prepared in advance to reduce the delay in establishing replication connections.
5.2.1. Resource Startup
5.2.2. Resource Stop
5.3. Change Settings
The settings in the DRX can be changed by changing the contents of the configuration file or by using the drx-ctl set command.
DRX does not provide commands to modify resource files or apply changes to files to change settings. Modifying a resource file is subject to manual intervention by the user.
5.3.1. Static Change Settings
The way users change the contents of a configuration file and restart resources is called a static change settings.
5.3.2. Dynamic Change Settings
Using the drx-ctl set command to change real-time settings during operation is called dynamic setting change. Settings through the set command are temporary, not reflected in the contents of the actual resource configuration file. The following is an example of the dynamic setting of the bwlimit.
The drx-ctl adjust command is a command for users to change the configuration file themselves and apply it dynamically during operation. The adjust command even starts the resource when it is in a down state.