KBEA-00078 - Configuring Accelerator with Autofs5

This article is not applicable to ElectricAccelerator versions 5.4 and later. Support for autofs5 was added in v5.4.

Summary

Accelerator versions prior to v5.4 do not support autofs5, which comes with RHEL5 and other newer distributions. This knowledge base article discusses how to configure the auto.master file so that Accelerator will work with the new Automounter.

Background

Accelerator versions prior to v5.4 do not support Automount 5 without additional manual configuration. Though autofs5 is significantly more stable than autofs4, there is no programmatic way to get autofs5 to mount files for the /efsroot agent sandboxes.

Autofs4 spawned a separate automount process for each entry in the auto.master file. For example, if there was an entry for /net and /home, then two automount processes would be started:

autmount processes

When the agent starts, it was able to see these automount processes and then swizzle the arguments around and start additional automount processes for all of the efsroot sandboxes. After the agents started, you would see the following processes for each of the agents. Note the /efsroot/0-1/ prepended to the /net.

swizzled automount processes

On autofs5 systems, there is only one process running, autmount, and it does not have any arguments to tell what directories it is managing. In addition, it is a multi-threaded application and no more automount processes can be started.

Solution

Indirect Mounts

A typical auto.master will have an entry like the following:

Add the following entries to auto.master for a machine that has four agents. You would create 0-7 if you had an 8 agent machine.

Electric Cloud highly recommends installing autofs 5.0.5 from ftp.kernel.org/pub/daemons/autofs/v5 because many issues have been experienced with earlier versions of the automounter. There was a non-Accelerator automount problem on an autofs 5.0.4 system that "magically" started working when it was upgraded to 5.0.5.

Direct Mounts

To support direct mounts (for example, your make file references /myShare/tools), you must create a separate file that is included in the auto.master as follows:

The auto.ecloud file contains the mapping for a direct mount, so if you have 4 agents, the entries would look like this:

Because the direct mounts must overlay the mounts already discovered by EFS, the agent daemon ecagent must start before the automounter daemon autofs. The following is an example of how this can be accomplished (for example, moving the agent daemon up in the list from S77 to S27 so it runs before the autofs daemon which is at S28):

Additional information about why the agent must start first:

Concerns

There is currently no known way to automatically configure Accelerator to work with autofs5 without modifying the /etc/auto.master file.

See Also

Autofs source repository

Applies to

  • Product versions: earlier than 5.4
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