# yum install -y kmod-drbd84 drbd84-utils Import the ELRepo package signing key, enable the repository and install the DRBD kernel module with utilities: # rpm -import DRBD can be understood as network based RAID-1. This is done by mirroring a whole block device via an assigned network. disable_ipv6 = 1 # sysctl -p DRBDĭRBD refers to block devices designed as a building block to form high availability clusters. We have also disabled IPv6, open /etc/nf for editing and place the following: .disable_ipv6 = 1 A INPUT -j REJECT -reject-with icmp-port-unreachable A INPUT -j LOG -log-prefix 'iptables_input ' A INPUT -m state -state RELATED,ESTABLISHED -j ACCEPT A INPUT -p udp -m multiport -dports 67,68 -m state -state NEW -j ACCEPT A INPUT -s 10.0.0.0/8 -p tcp -m tcp -dport 22 -m state -state NEW -j ACCEPT These are iptables rules that we have in use: # iptables -S The o2cb cluster stack requires iptables to be either disabled or modified to allow network traffic on the private network interface. We have set the following hostnames: # hostnamectl set-hostname ora1 Hostnames and IPs as defined in /etc/hosts file: 10.8.8.55 ora1 172.16.22.0/24 – non-routable cluster heartbeat vlan for DRBD.172.16.21.0/24 – non-routable cluster heartbeat vlan for o2cb,.10.8.8.0/24 – LAN with access to the Internet,.We have two Oracle Linux 7 virtual machines on VirtualBox, named ora1 and ora2. Oracle Linux Server release 7.2 (Maipo).The convention followed in the article is that # denotes a command that needs to be run on all cluster nodes. Both files are only read when the cluster is brought online. Whereas the former keeps track of the cluster layout, the latter keeps track of the cluster timeouts. This cluster stack has two configuration files, /etc/ocfs2/nf and /etc/sysconfig/o2cb. It also includes a synthetic file system, dlmfs, to allow applications to access the in-kernel dlm. It is an in-kernel cluster stack that includes a node manager (o2nm) to keep track of the nodes in the cluster, a disk heartbeat agent (o2hb) to detect node live-ness, a network agent (o2net) for intra-cluster node communication and a distributed lock manager (o2dlm) to keep track of lock resources. The o2cb is the default cluster stack of the OCFS2 file system. We are going to build a two-node active/active HA cluster using O2CB and DRBD.

Oracle linux cluster configuration