RHEL5, GFS2 and DRBD8

I've finally built my first cluster on rhel5 using gfs2 and drbd8 :-D

drbd makes a network raid1 between two physical distinguished block devices (eg. internal disks of two servers) and from the release 8.0 it supports the active/active configuration.

gfs2 permits to the two server machines a concurrent mount of the network replicated drbd device.

rhel5 is the OS I've installed on the two machines.

Practically with this stuff the servers share the same "storage". Here is a sample config file for drbd:

common { syncer { rate 100M; } }
resource r0 {
  protocol C;
  disk { on-io-error pass_on; }
  net {
    allow-two-primaries;
    after-sb-0pri discard-least-changes;
    after-sb-1pri discard-secondary;
    after-sb-2pri violently-as0p;
  }
  on bsvm1.babel.int {
    address 192.168.1.1:7790;
    disk /dev/mapper/ddf1_ld0p5;
    device /dev/drbd0;
    meta-disk "internal";
  }
  on bsvm1.babel.int {
    address 192.168.1.2:7790;
    disk /dev/mapper/ddf1_ld0p5;
    device /dev/drbd0;
    meta-disk "internal";
  }
}

Want to give it a try? Configure your cluster.xml file, start the drbd and cman services, create the filesystem on the drbd device and ... have fun!!