Pivotal Knowledge Base


New cflinuxfs2 Stack

Pivotal Cloud Foundry® applications run in containers that use an operating system file system image called a stack. Versions of Pivotal Cloud Foundry Elastic Runtime 1.4 and later support a new stack, cflinuxfs2, which is derived from Ubuntu Trusty 14.04.

The lucid64 stack, which has been part of Pivotal Cloud Foundry (PCF) Elastic Runtime for several years, will reach Canonical’s end of support for security fixes on April 29th, 2015.

Developers or operators must take action to ensure that their applications use the new stack. Applications using the lucid64 stack continue to function in Elastic Runtime 1.5, but the lucid64 stack will be removed from Elastic Runtime 1.6. Your stack change should be planned and executed before the upgrade to Elastic Runtime 1.6 or above, or applications that have not switched to cflinuxfs2 will be unable to start after the upgrade. Pivotal recommends using a blue/green deployment strategy to ensure there is no down time for the app.

If applications are unable to start because lucid64 is no longer available, changing the stack of those applications to cflinuxfs2 should correct the issue. 

Do you need to take action?

New installations of PCF that began with Elastic Runtime version 1.5 use only the cflinuxfs2 stack. No action is required. However, if an installation is currently running Elastic Runtime version 1.5 after upgrading from an earlier version, it may include apps that are still running on the old stack. Developers or operators of an installation that upgraded to Elastic Runtime 1.5 from an earlier version should follow the procedure described below for ensuring that all apps use the new stack.


PCF Elastic Runtime 1.4 installations use the new cflinuxfs2 stack by default. Any PCF installation that started with Elastic Runtime 1.4 does not need to take action unless the installation uses the non-default lucid64 stack. If the operator selected the lucid64 stack option, see the below instructions for migrating to the new stack.

Operators of installations of Elastic Runtime starting with version 1.3 and prior must take action to migrate to the new stack.

Migrating to the new stack

Pivotal recommends using the stack-changer cf CLI plugin. The following instructions describe the procedure using the plugin.

Note: You must run the stack-changer cf CLI plugin as an admin user.

  1. Determine whether your buildpack supports the new stack. All of the system buildpacks support the new cflinuxfs2 stack, including Java, NodeJS, PHP, Go, Python, and Ruby. If you have custom buildpacks, ensure that they are compatible with the new cflinuxfs2 stack.
  2. Upgrade to Elastic Runtime 1.5 by following the procedure in the Upgrading Products topic. After the tile is upgraded, new applications will use the cflinuxfs2 stack.
  3. Install the plugin.
  4. Run cf stack-list to list all apps running on the old lucid64 stack.
  5. Update any pre-existing applications that were using the lucid64 stack to use the new cflinuxfs2 stack. Run cf stack-change -o ORG_NAME -s SPACE_NAME to migrate all apps in the specified org and space to the new stack.

Alternatively, you can migrate an app to the new stack without the plugin. However, this procedure will result in a small amount of down time as old instances are stopped and the app is restaged with the new stack.

  1. Run cf app APP_NAME to view information about the named app, including the current stack.
  2. Run cf push APP_NAME -s cflinuxfs2 to restage your app with the new stack.  

Notify users of lucid64 end of life

Operators should decide when to notify lucid64 stack users that they will be vulnerable to not getting new security patches once lucid64 reaches end of support. Developers or operators should migrate their applications before deploying Elastic Runtime 1.6.




  • Avatar
    Amulya Sharma

    This article saved us from the outage we had after the stack upgrade ..

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