4.3. Creating the resources and resource groups

1. An LVM-activate resource named my_lvm that uses the LVM volume group you created in Configuring an LVM volume with an XFS file system in a Pacemaker cluster.
2. A Filesystem resource named my_fs, that uses the file system device /dev/my_vg/my_lv you created in Configuring an LVM volume with an XFS file system in a Pacemaker cluster.
3. An IPaddr2 resource, which is a floating IP address for the apachegroup resource group. The IP address must not be one already associated with a physical node. If the IPaddr2 resource’s NIC device is not specified, the floating IP must reside on the same network as one of the node’s statically assigned IP addresses, otherwise the NIC device to assign the floating IP address cannot be properly detected.
4. An apache resource named Website that uses the index.html file and the Apache configuration you defined in Configuring an Apache HTTP server.

Procedure

1. The following command creates the LVM-activate resource my_lvm. Because the resource group apachegroup does not yet exist, this command creates the resource group.

   注意

   Do not configure more than one LVM-activate resource that uses the same LVM volume group in an active/passive HA configuration, as this could cause data corruption. Additionally, do not configure an LVM-activate resource as a clone resource in an active/passive HA configuration.

   [root@z1 ~]# pcs resource create my_lvm ocf:heartbeat:LVM-activate vgname=my_vg vg_access_mode=system_id --group apachegroup

   When you create a resource, the resource is started automatically. You can use the following command to confirm that the resource was created and has started.

   # pcs resource status
    Resource Group: apachegroup
        my_lvm	(ocf::heartbeat:LVM-activate):	Started

   You can manually stop and start an individual resource with the pcs resource disable and pcs resource enable commands.

2. The following commands create the remaining resources for the configuration, adding them to the existing resource group apachegroup.

   [root@z1 ~]# pcs resource create my_fs Filesystem device="/dev/my_vg/my_lv" directory="/var/www" fstype="xfs" --group apachegroup
   
   [root@z1 ~]# pcs resource create VirtualIP IPaddr2 ip=198.51.100.3 cidr_netmask=24 --group apachegroup
   
   [root@z1 ~]# pcs resource create Website apache configfile="/etc/httpd/conf/httpd.conf" statusurl="http://127.0.0.1/server-status" --group apachegroup

3. After creating the resources and the resource group that contains them, you can check the status of the cluster. Note that all four resources are running on the same node.

   [root@z1 ~]# pcs status
   Cluster name: my_cluster
   Last updated: Wed Jul 31 16:38:51 2013
   Last change: Wed Jul 31 16:42:14 2013 via crm_attribute on z1.example.com
   Stack: corosync
   Current DC: z2.example.com (2) - partition with quorum
   Version: 1.1.10-5.el7-9abe687
   2 Nodes configured
   6 Resources configured
   
   Online: [ z1.example.com z2.example.com ]
   
   Full list of resources:
    myapc	(stonith:fence_apc_snmp):	Started z1.example.com
    Resource Group: apachegroup
        my_lvm	(ocf::heartbeat:LVM-activate):	Started z1.example.com
        my_fs	(ocf::heartbeat:Filesystem):	Started z1.example.com
        VirtualIP	(ocf::heartbeat:IPaddr2):	Started z1.example.com
        Website	(ocf::heartbeat:apache):	Started z1.example.com

   Note that if you have not configured a fencing device for your cluster, by default the resources do not start.

4. Once the cluster is up and running, you can point a browser to the IP address you defined as the IPaddr2 resource to view the sample display, consisting of the simple word "Hello".

   Hello

   If you find that the resources you configured are not running, you can run the pcs resource debug-start resource command to test the resource configuration.

5. When you use the apache resource agent to manage Apache, it does not use systemd. Because of this, you must edit the logrotate script supplied with Apache so that it does not use systemctl to reload Apache.

   Remove the following line in the /etc/logrotate.d/httpd file on each node in the cluster.

   /bin/systemctl reload httpd.service > /dev/null 2>/dev/null || true

   Replace the line you removed with the following three lines, specifying /var/run/httpd-website.pid as the PID file path where website is the name of the Apache resource. In this example, the Apache resource name is Website.

   /usr/bin/test -f /var/run/httpd-Website.pid >/dev/null 2>/dev/null &&
   /usr/bin/ps -q $(/usr/bin/cat /var/run/httpd-Website.pid) >/dev/null 2>/dev/null &&
   /usr/sbin/httpd -f /etc/httpd/conf/httpd.conf -c "PidFile /var/run/httpd-Website.pid" -k graceful > /dev/null 2>/dev/null || true