Chapter 3. Installing and configuring Relax and Recover (ReaR)

Procedure

1. Install the ReaR packages and packages for generating ISO images on the undercloud node and on each control plane node:

   [root@controller-x ~]# yum install rear genisoimage nfs-utils -y

2. To avoid upgrade issues in the future, delete the scheduled ReaR cron task:

   [root@controller-x ~]# rm -f /etc/cron.d/rear

3. Create a backup directory on the undercloud and on each control plane node:

   [root@controller-x ~]# mkdir -p /ctl_plane_backups

4. Mount the ctl_plane_backups NFS directory from the backup node that runs NFS on the undercloud and on each control plane node:

   [root@controller-x ~]# mount -t nfs  <BACKUP_NODE_IP_ADDRESS>:/ctl_plane_backups /ctl_plane_backups

   Replace <BACKUP_NODE_IP_ADDRESS> with the IP address of the backup node running the NFS server.

Procedure

1. Create the ReaR configuration file:

   [root@controller-x ~]# mkdir -p /etc/rear
   [root@controller-x ~]# tee -a "/etc/rear/local.conf" > /dev/null <<'EOF'
   OUTPUT=ISO
   OUTPUT_URL=nfs://<BACKUP_NODE_IP_ADDRESS>/ctl_plane_backups
   ISO_PREFIX=<NODE_HOSTNAME>
   BACKUP=NETFS
   BACKUP_PROG_COMPRESS_OPTIONS=( --gzip )
   BACKUP_PROG_COMPRESS_SUFFIX=".gz"
   BACKUP_PROG_EXCLUDE=( '/tmp/*' '/data/*' )
   BACKUP_URL=nfs://<BACKUP_NODE_IP_ADDRESS>/ctl_plane_backups
   BACKUP_PROG_EXCLUDE=("${BACKUP_PROG_EXCLUDE[@]}" '/media' '/var/tmp' '/var/crash')
   BACKUP_PROG_OPTIONS+=( --anchored --xattrs-include='*.*' --xattrs )
   EOF

   • Replace <NODE_HOSTNAME> with the hostname of the node. For example, if the node hostname is controller-0, replace <NODE_HOSTNAME> with controller-0.

   • Replace <BACKUP_NODE_IP_ADDRESS> with the IP address of the backup node that runs the NFS server. This is the IP address that you configured when you prepared the backup node. For more information, see Chapter 2, Prepare the Backup Node.

     Important

     If the undercloud or control plane nodes use boot mode UEFI, you must add USING_UEFI_BOOTLOADER=1 to the configuration file.

2. If you use an OVS bridge for your network interfaces, add the following configuration to the /etc/rear/local.conf file to enable the recovery process to retrieve the backups through the network:

   NETWORKING_PREPARATION_COMMANDS=('<command_1>' '<command_2>' ... '<command_n>')

   Replace <command_1>, and all commands up to <command_n>, with the commands that you need to configure your network configuration, for example:

   • To configure the control plane bridge name, add the ip link add br-ctlplane type bridge command.
   • To set the name of the interface, add the ip link set eth0 up command.

3. Create the rescue.conf file:

   [root@controller-x ~]# tee  -a "/etc/rear/rescue.conf" > /dev/null <<'EOF'
   BACKUP_PROG_OPTIONS+=( --anchored --xattrs-include='*.*' --xattrs )
   EOF