[linux] two-node-ha-centos

使用虚拟机构建双节点Linux-HA实验
操作系统： CentOS7
虚拟机器： KVM

1. 系统安装

1.1 选择最小化安装
    两虚拟机器分别命名为node1和node2
    node1 192.168.122.100
    node2 192.168.122.101
    公共的虚拟IP为 node.cst 192.168.122.110

1.2 使用光盘文件作为软件仓库
    挂在光盘文件到 /mnt目录
    #/etc/yum.repos.d/CentOS-Media.repo
[c7-media]
name=CentOS-$releasever - Media
baseurl=file:///mnt/
gpgcheck=1
enabled=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7

1.3 设置hosts文件
    在 /etc/hosts中添加
192.168.122.100    node1
192.168.122.101    node2
192.168.122.110    node.cst

1.4 设置ssh互信
    [node1:] ssh-keygen -t rsa -P ''
    [node1:] ssh-copy-id -i .ssh/id_rsa.pub root@node2
    [node2:] ssh-keygen -t rsa -P ''
    [node2:] ssh-copy-id -i .ssh/id_rsa.pub root@node1

2. 软件安装与配置

2.1 安装pacemaker
    [all:] yum -y install pcs policycoreutils-python fence-agents-all firwalld

2.2 配置防火墙
    [all:] systemctl start firewalld.service
    [all:] systemctl enable firewalld.service
    [all:] firewall-cmd --permanent --add-service=high-availability
    [all:] firewall-cmd --add-service=high-availability
    [all:] firewall-cmd --reload

2.3 配置集群
    [all:] systemctl start pcsd
    [all:] systemctl enable pcsd
    [all:] passwd hacluster -- 设置hacluster账户密码
    [nodeX:] pcs cluster auth node1 node2 -- 集群节点认证，用户名为hacluster
    [nodeX:] pcs cluster setup --name node.cst node1 node2
    [nodeX:] pcs cluster enable --all
    [nodeX:] pcs cluster status

2.4 配置fence_xvm作为fence_agent设备 -- 主机
    [hosts:] yum -y install fence-virt*
    [hosts:] mkdir -p /etc/cluster
    [hosts:] dd if=/dev/urandom of=/etc/cluster/fence_xvm.key bs=4k count=1
    [hosts:] scp -r /etc/cluster/fence_xvm.key root@node1:/etc/cluster/fence_xvm.key
    [hosts:] scp -r /etc/cluster/fence_xvm.key root@node2:/etc/cluster/fence_xvm.key
    [hosts:] fence_virtd -c
#/etc/fence_virt.conf -- interface为与KVM虚拟机通信的设备
backends {
        libvirt {
                uri = "qemu:///system";
        }

}

listeners {
        multicast {
                interface = "virbr0";
                port = "1229";
                family = "ipv4";
                address = "225.0.0.12";
                key_file = "/etc/cluster/fence_xvm.key";
        }

}

fence_virtd {
        module_path = "/usr/lib64/fence-virt";
        backend = "libvirt";
        listener = "multicast";
}

2.5 启动主机端fence_xvm服务
    [host:] systemctl enable fence_virtd
    [host:] systemctl start fence_virtd
    [host:] systemctl status fence_virtd

2.6 配置虚拟机fence_xvm设置
    [all:] yum -y install fence-virt
    [nodeX:] fence_xvm -o list #在客户机上获得当前所有虚拟机名,该虚拟机名称必须在/etc/hosts中有配置
    [node1:] fence_xvm -a 225.0.0.12 -k /etc/cluster/fence_xvm.key -H node2 -o status #获得node2状态
    [node1:] fence_xvm -a 225.0.0.12 -k /etc/cluster/fence_xvm.key -H node2 -o reboot #node2重新启动
    [node2:] fence_xvm -a 225.0.0.12 -k /etc/cluster/fence_xvm.key -H node1 -o status #获得node1状态
    [node2:] fence_xvm -a 225.0.0.12 -k /etc/cluster/fence_xvm.key -H node1 -o reboot #node1重新启动

2.7 设置HA的stonith
    [nodeX:] pcs stonith create node.fence fence_xvm key_file=/etc/cluster/fence_xvm.key
    [nodeX:] pcs stonith --full
    [nodeX:] pcs property set stonith-enabled=true
    [nodeX:] pcs stonith
    [node2:] pcs stonith fence node1  #验证stonith,结果为node1重启
    [node2:] pcs property --all | grep stonith-action

2.8 设置虚拟ip地址
    设置群组 node.grp,在相同group内的资源在统一个节点上启动
    [nodeX:] pcs resource create node.ip IPaddr2 ip=192.168.122.110 cidr_netmask=24 op monitor interval=30s --group node.grp
    [nodeX:] pcs status
    [all:] ip a

2.9 配置drbd
    [all:] rpm -ivh drbd84-utils-8.9.6-1.el7.elrepo.x86_64.rpm
    [all:] rpm -ivh kmod-drbd84-8.4.8-1_1.el7.elrepo.x86_64.rpm
    [all:] echo "drbd" > /etc/modules-load.d/drdb.conf
    [all:] firewall-cmd --permanent --zone=trusted --add-source=192.168.122.0/24
    [all:] firewall-cmd --reload
    [all:] firewall-cmd --zone=trusted --list-source
    [all:] semanage permissive -a drbd_t #设置selinux
#/etc/drbd.d/node.db.res
resource node.db{
    protocol C;
    meta-disk internal;
    device /dev/drbd0;
    disk /dev/vdb;
    syncer{
        verify-alg sha1;
    }
    net{
        allow-two-primaries;
    }
    on node1{
        address 192.168.122.100:7789;
    }
    on node2{
        address 192.168.122.101:7789;
    }
    
}

2.10 启动drbd
    [all:] drbdadm create-md node.db
    [all:] modprobe drbd
    [all:] drbdadm up node.db
    [all:] cat /proc/drbd
    [node1:] drbdadm primary --force node.db
    [nodeX:] cat /proc/drbd
    [node1:] mkfs.ext4 /dev/drbd0
    [all] mkdir /node.fs
    [node1:] mount /dev/drbd0 /node.fs
    [node1:] echo "from node1" > /node.fs/test
    [node1:] drbdadm secondary node.db
    [node2:] drbdadm primary node.db
    [node2:] mount /dev/drbd0 /node.fs
    [node2:] cat /node.fs/test
    [node2:] echo "from node2" >> /node.fs/test

2.11 设置drbd资源
    [nodeX:] pcs cluster cib drbd_cfg
    [nodeX:] pcs -f drbd_cfg resource create node.db ocf:linbit:drbd drbd_resource=node.db op monitor interval=60s --group node.grp
    [nodeX:] pcs -f drbd_cfg resource master node.db.clone node.db master-max=1 master-node-max=1 clone-max=2 clone-node-max=1 notify=true --group node.grp
    [nodeX:] pcs -f drbd_cfg resource show
    [nodeX:] pcs -f pcs cluster cib-push drbc_cfg

2.12 设置文件系统资源
    [nodeX:] pcs cluster cib fs_cfg
    [nodeX:] pcs -f fs_cfg resource create node.fs Filesystem device="/dev/drbd0" directory="/node.fs" fstype="ext4" --group node.grp
    [nodeX:] pcs -f fs_cfg constraint colocation add node.fs with node.db.clone INFINITY with-rsc-role=Master
    [nodeX:] pcs -f fs_cfg constraint order promote node.db.clone then start node.fs
    [nodeX:] pcs -f fs_cfg constraint colocation add node.ip with node.db.clone INFINITY with-rsc-role=Master
    [nodeX:] pcs -f fs_cfg resource show
    [nodeX:] pcs -f pcs cluster cib-push fs_cfg
    [nodeX:] pcs status