Linux-ha Open source software heartbeat installation

First, the preparation before installing heartbeat

1. Hardware required for heartbeat cluster

The hardware devices necessary to build a heartbeat cluster system are:

Node server

Networks and network adapters

Shared disks

(1) Node server

Installation of heartbeat requires at least two hosts, and the requirements of the host is not high, ordinary PC server can meet the requirements, of course, can also be installed on the virtual machine heartbeat, now heartbeat can be very well run under the Linux system, Many Linux distributions have their own heartbeat suite, and can also run on FreeBSD and Solaris operating systems.

(2) NIC and network

Heartbeat cluster in each host must have a network card and a free serial port, network card used to connect the public network, the serial port can be connected through the serial port, such as modem wire to achieve the status of heartbeat monitoring nodes, if there is no free serial port, each host can also through two cards to achieve ha , one of which is used to connect to the public network, and the other is connected to two nodes via an Ethernet crossover line.

Need to explain: Ethernet crossover line and serial wire can be used for heartbeat monitoring, serial wire transmission heartbeat signal is relatively good, if conditions, as far as possible, use the serial line instead of Ethernet crossover as the heartbeat detection equipment between nodes.

Heartbeat supports three types of networks, public network, private network (private network), and serial Network (serial network).

Public networks connect multiple nodes and allow clients to access service nodes in the cluster, private networks provide point-to-point access between two nodes, but do not allow client access, you can build a private network through an Ethernet crossover to communicate between nodes, and the serial network is a point-to-point connection, A serial network is generally used to transmit control information and heartbeat monitoring. A serial network can be a RS232 serial line.

(3) Shared disk

A shared disk is a data storage device in which all nodes in the HA cluster need to be connected to the storage device, where common, critical data and programs are commonly placed on the shared storage device, while data can be shared with all nodes and the security of the data is ensured.

Heartbeat supports two ways to access a shared disk: exclusive access and shared access, where the active node uses the disk device independently, and only if the active node releases the disk device, other nodes can take over the disk, and in the shared access mode, All nodes of a cluster can use a disk device at the same time, and when a node fails, the other nodes do not have to take over the disk. Shared access requires the support of a clustered file system, which is described in the next section.

2. Operating system planning

The red Hat Enterprise Linux Server Release 5.1 operating system is unified here, with two network cards per node server, one for connection to the public network, and another for two nodes via Ethernet crossover, as heartbeat monitoring. The shared disk is provided by a single disk array device, and two nodes share a single disk partition. The disk partition corresponds to the hardware identified as/DEV/SDB5, the mount point is/webdata, and the file system type is ext3.

Network and IP address planning are shown in table 1:

Table 1