The crm shell is a command-line interface to the Pacemaker cluster resource management stack. If that doesn’t make any sense to you, the easiest way to get up to speed is to go to the Pacemaker website and read more about what it does there.

The crm shell provides a simpler interface to configuring Pacemaker than manipulating the XML of the CIB (Cluster Information Base) directly. With its command-line style interface, changes to the cluster can be performed quickly and painlessly. It also works as a scripting tool, allowing more complicated changes to be applied to the cluster.

The crm shell also functions as a management console, providing a unified interface to a number of other auxilliary tools related to Pacemaker and cluster management.

Many distributions provide packages for the crm shell in their respective package repositories. The best and safest way to obtain the crm shell is via the distribution repositories, so look there first.

The intention is for the crm shell to work well on all the major distributions. Pre-built packages are provided for the following distros:

More information can be found on the Documentation page.

Yes, initially, the crm shell was distributed as part of the Pacemaker project. It was split into its own, separate project in 2011.

A common misconception is that crm has been replaced by pcs (available at github.com/feist/pcs). pcs is an alternative command line interface similar to crm. Both projects are being actively developed, with slightly different goals. Our recommendation is to use whatever shell your distribution of choice comes with and supports, unless you have a particular preference or are on a distribution which doesn’t bundle either. In that case, we are obviously biased towards one of the available choices. ;)

Yes! Take a look at Hawk.

Hawk uses the crm shell as its backend to interact with the cluster.