PureMessage for UNIX: Configuring High Availability with a Storage Area Network

  • Article ID: 113878
  • Updated: 20 Jan 2012

If you want to create a standby PureMessage server by means of a storage area network (SAN), you can specify this when installing PureMessage.

High availability by way of SAN requires two servers that are using identical hardware. The second server can be substituted in the event that the first server fails.

To configure high availability via SAN:

  1. Install PureMessage on a mounted SAN share (provide the installation directory when prompted by the PureMessage installer).
  2. Use a hard disk duplication tool to copy the installation to a second server. If you do not create an exact copy of the installation, you must take steps to ensure that the configuration of the second server is identical to the first. On both servers, all of the following must match:

    • IP address and hostname
    • UID and GUID
    • Operating system and OS version
    • PureMesssage user and PureMessage group user
    • Postfix user and Postfix group user
    • postdrop group user

    You must also ensure that, on both servers:

    • The etc/puremessage-6 file contains the location of the PureMessage installation.
    • Ownership of the installation directory (for example, /opt/pmx6) must be root:pmx_user.

    Important: Since these servers are identical, they should never be running at the same time. For example, if you want to test to ensure that your standby server is configured correctly, turn off the first server before turning on the second server.

  3. [Optional] If you also require mail log to be written to the SAN, you must:

    • Configure syslog to ensure that the mail log is written to the SAN.
    • Update the mail log setting in PureMessageInstallDir/etc/logsearch.conf to point to the correct location.

Switching to the Standby Server

If you need or want to switch to the standby server, perform these steps:

  1. On the primary server, ensure that PureMessage is stopped, and the server is powered off.
  2. Power on the standby server, and start PureMessage from the command line as the PureMessage user.

    pmx start

  3. On the standby server, start the mail transfer agent from the command line as the PureMessage user.

    pmx-service start smtp

  4. Test the server to confirm that it is operating correctly.

If you need more information or guidance, then please contact technical support.

Rate this article

Very poor Excellent