Upgrading Cumulus Linux

This topic describes how to upgrade Cumulus Linux on your switch.

Consider deploying, provisioning, configuring, and upgrading switches using automation, even with small networks or test labs. During the upgrade process, you can quickly upgrade dozens of devices in a repeatable manner. Using tools like Ansible, Chef, or Puppet for configuration management greatly increases the speed and accuracy of the next major upgrade; these tools also enable the quick swap of failed switch hardware.

Before You Upgrade

Back up Configuration Files

Understanding the location of configuration data is required for successful upgrades, migrations, and backup. As with other Linux distributions, the /etc directory is the primary location for all configuration data in Cumulus Linux. The following list is a likely set of files that you need to back up and migrate to a new release. Make sure you examine any file that has been changed. Consider making the following files and directories part of a backup strategy.

Create a cl-support File

Before and after you upgrade the switch, run the cl-support script to create a cl-support archive file. The file is a compressed archive of useful information for troubleshooting. If you experience any issues during upgrade, you can send this archive file to the Cumulus Linux support team to investigate.

1. Create the cl-support archive file with the cl-support command:

   cumulus@switch:~$ sudo cl-support
   

2. Copy the cl-support file off the switch to a different location.

3. After upgrade is complete, run the cl-support command again to create a new archive file:

   cumulus@switch:~$ sudo cl-support
   

Upgrade Cumulus Linux

To upgrade to Cumulus Linux 4.0 from Cumulus Linux 3.7, you must install a disk image of the new release using ONIE. You cannot upgrade packages with the apt-get upgrade command.

ONIE is an open source project (equivalent to PXE on servers) that enables the installation of network operating systems (NOS) on a bare metal switch.

Be aware of the following when installing the disk image:

• Installing a disk image is destructive; any configuration files on the switch are not saved; copy them to a different server before you start installation.
• You must move configuration data to the new OS using ZTP or automation while the OS is first booted, or soon afterwards using out-of-band management.
• Moving a configuration file might cause issues:
  • Identifying all the locations of configuration data is not always an easy task. See Before You Upgrade above.
  • Merge conflicts with configuration file changes in the new release might go undetected.
• If configuration files are not restored correctly, you might be unable to ssh to the switch from in-band management. Out-of-band connectivity (eth0 or console) is recommended.
• You must reinstall and reconfigure third-party applications after upgrade.

To upgrade the switch:

1. Back up the configurations off the switch.

2. Download the Cumulus Linux image.

3. Install the disk image with the onie-install -a -i <image-location> command, which boots the switch into ONIE. The following example command installs the image from a web server, then reboots the switch. There are additional ways to install the disk image, such as using FTP, TFTP, a local file, or a USB drive. For more information, see Installing a New Cumulus Linux Image.

   cumulus@switch:~$ sudo onie-install -a -i http://10.0.1.251/cumulus-linux-4.0.0-mlx-amd64.bin && sudo reboot
   

4. Restore the configuration files to the new release - ideally with automation.

5. Verify correct operation with the old configurations on the new release.

6. Reinstall third party applications and associated configurations.

Upgrade Switches in an MLAG Pair

If you are using MLAG to dual connect two switches in your environment, follow the steps below to upgrade the switches.

1. Verify the switch is in the secondary role:

   cumulus@switch:~$ clagctl status
   

2. Shut down the core uplink layer 3 interfaces:

   cumulus@switch:~$ sudo ip link set swpX down
   

3. Shut down the peer link:

   cumulus@switch:~$ sudo ip link set peerlink down
   

4. To boot the switch into ONIE, run the onie-install -a -i <image-location> command. The following example command installs the image from a web server. There are additional ways to install the Cumulus Linux image, such as using FTP, a local file, or a USB drive. For more information, see Installing a New Cumulus Linux Image.

   cumulus@switch:~$ sudo onie-install -a -i http://10.0.1.251/downloads/cumulus-linux-4.1.0-mlx-amd64.bin
   

   To upgrade the switch with package upgrade instead of booting into ONIE, run the sudo -E apt-get update and sudo -E apt-get upgrade commands; see Package Upgrade.

5. Reboot the switch:

   cumulus@switch:~$ sudo reboot
   

6. If you installed a new image on the switch, restore the configuration files to the new release.

7. Verify STP convergence across both switches:

   cumulus@switch:~$ mstpctl showall
   

8. Verify core uplinks and peer links are UP:

   cumulus@switch:~$ net show interface
   

9. Verify MLAG convergence:

   cumulus@switch:~$ clagctl status
   

10. Make this secondary switch the primary:

cumulus@switch:~$ clagctl priority 2048

11. Verify the other switch is now in the secondary role.

12. Repeat steps 2-9 on the new secondary switch.

13. Remove the priority 2048 and restore the priority back to 32768 on the current primary switch:

    cumulus@switch:~$ clagctl priority 32768
    

Roll Back a Cumulus Linux Installation

Even the most well planned and tested upgrades can result in unforeseen problems; sometimes the best solution is to roll back to the previous state. There are three main strategies; all require detailed planning and execution:

• Flatten and rebuild: If the OS becomes unusable, you can use orchestration tools to reinstall the previous OS release from scratch and then rebuild the configuration automatically.
• Backup and restore: Another common strategy is to restore to a previous state using a backup captured before the upgrade. See Back up and Restore.

The method you employ is specific to your deployment strategy, so providing detailed steps for each scenario is outside the scope of this document.

Third Party Packages

Third party packages in the Linux host world often use the same package system as the distribution into which it is to be installed (for example, Debian uses apt-get). Or, the package might be compiled and installed by the system administrator. Configuration and executable files generally follow the same filesystem hierarchy standards as other applications.

If you install any third party applications on a Cumulus Linux switch, configuration data is typically installed into the /etc directory, but it is not guaranteed. It is your responsibility to understand the behavior and configuration file information of any third party packages installed on the switch.

After you upgrade using a full disk image install, you need to reinstall any third party packages or any Cumulus Linux add-on packages.

Related Information

• Upgrades: Network Device Worldview and Linux Host Worldview Comparison
• Automation Solutions
• ONIE Design Specification
• Multi-Chassis Link Aggregation - MLAG
• Zero Touch Provisioning - ZTP