In the previous section, we went over using drbdsteup. drbd also allows you to setup everything in a drbd.conf file. By correctly configuring this file and using the init.d/drbd script you can easily make drbd come up correctly when a machine boots up.
In this configuration, we have 2 machines named thost1 and thost2. The IP address for thost1 is 10.1.1.31, and the IP address for thost2 is 10.1.1.32. We want to create a mirror between /dev/hda7 on thost1, and /dev/hda7 on machine thost2. Here is a sample /etc/drbd.conf file to accomplish this:
resource drbd0 { protocol=B fsck-cmd=fsck.ext2 -p -y on thost1 { device=/dev/nb0 disk=/dev/hda7 address=10.1.1.31 port=7789 } on thost2 { device=/dev/nb0 disk=/dev/hda7 address=10.1.1.32 port=7789 } }
After you create the drbd.conf file, go to thost1, and run the following command:
$ /etc/rc.d/init.d/drbd start
Do the same thing on thost2
$ /etc/rc.d/init.d/drbd start
At this point, you should have a mirror between the 2 devices. You can verify this by looking at /proc/drbd
$ cat /proc/drbd
Now you can make a filesystem on the device, and mount it on machine thost1.
$ mkfs /dev/nb0 $ mount /dev/nb0 /mnt/disk
At this point, you have now created a mirror using drbd. Congrats. To move ahead with creating a highly available failover system, look into the the scripts subdirectory and integrate with the heartbeat software available at linux-ha.org