pacemaker/doc/Pacemaker_Explained/en-US/Ap-FAQ.txt

[appendix]

[[ap-faq]]
== FAQ ==


[qanda]
Why is the Project Called Pacemaker?::
 indexterm:[Pacemaker]
 First of all, the reason it's not called the CRM is because of the abundance
 of terms footnote:[http://en.wikipedia.org/wiki/CRM] that are commonly
 abbreviated to those three letters. The Pacemaker name came from Kham,
 footnote:[http://khamsouk.souvanlasy.com/] a good friend of Pacemaker
 developer Andrew Beekhof's, and was originally used by a Java GUI that Beekhof
 was prototyping in early 2007. Alas, other commitments prevented the GUI from
 progressing much and, when it came time to choose a name for this project,
 Lars Marowsky-Bree suggested it was an even better fit for an independent CRM.
 The idea stems from the analogy between the role of this software and that of
 the little device that keeps the human heart pumping.  Pacemaker monitors the
 cluster and intervenes when necessary to ensure the smooth operation of the
 services it provides.
 There were a number of other names (and acronyms) tossed around, but suffice to
 say "Pacemaker" was the best.

Why was the Pacemaker Project Created?::

 The decision was made to spin-off the CRM into its own project after the 2.1.3
 Heartbeat release in order to:

 * support both the Corosync and Heartbeat cluster stacks equally
 * decouple the release cycles of two projects at very different stages of their life-cycles
 * foster clearer package boundaries, thus leading to better and more stable interfaces

What Messaging Layers are Supported?::
 indexterm:[Messaging Layers]

 * http://www.corosync.org/[Corosync]
 * http://linux-ha.org/[Heartbeat]

Can I Choose Which Messaging Layer to Use at Run Time?::

 Yes. The CRM will automatically detect which started it and behave accordingly.

Can I Have a Mixed Heartbeat-Corosync Cluster?::

 No.

[[q-messaging-layer]] Which Messaging Layer Should I Choose?::
 indexterm:[Cluster,Choosing Between Heartbeat and Corosync]
 indexterm:[Cluster Stack,Corosync] indexterm:[Corosync]
 indexterm:[Cluster Stack,Heartbeat] indexterm:[Heartbeat]
 You can choose from multiple messaging layers, including
 heartbeat, corosync 1 (with or without CMAN), and corosync 2.
 Corosync 2 is the current state of the art due to its
 more advanced features and better support for pacemaker,
 but often the best choice is to use whatever comes with
 your Linux distribution, and follow the distribution's
 setup instructions.

Where Can I Get Pre-built Packages?::

 Most major Linux distributions have pacemaker packages in their standard
 package repositories. See the http://clusterlabs.org/wiki/Install[Install wiki
 page] for details.

What Versions of Pacemaker Are Supported?::

 Some Linux distributions (such as Red Hat Enterprise Linux and SUSE Linux
 Enterprise) offer technical support for their customers; contact them
 for details of such support.
 For help within the community (mailing lists, IRC, etc.) from Pacemaker developers
 and users, refer to the http://clusterlabs.org/wiki/Releases[Releases wiki page]
 for an up-to-date list of versions considered to be supported by the project.
 When seeking assistance, please try to ensure you have one of these versions.