Karbon Airgap (dark site) FAQ and Guide

FAQs

1. What is the Airgap feature?

Airgap feature is useful for customers in a dark site environment without Internet access or with relatively low Internet bandwidth that would like to use Karbon. Up until the introduction of the Airgap feature, Karbon was only available with sites connected to the Internet. The Airgap feature is also helpful for customers that face Karbon cluster deployment timeouts due to slow image pull speeds.

2. When was the Airgap feature introduced?

Karbon 2.0版。

3. How to enable Airgap mode for Karbon?

Please refer to Karbon Admin Guide (here) for the latest instructions. As of Karbon 2.0: Karbon Airgap is enabled viakarbonctl. The overview of the process of Karbon 2.0, is as follows:

1. The Airgap bundle is downloaded from the Nutanix Portal and extracted to a directory on a web server accessible from Prism Central.

2. Usingkarbonctl, perform aloginto authenticate with the Prism Central username and password. Logging in prevents the need to repeatedly provide the login information for eachkarbonctlcommand.

3. Usingkarbonctl, enable Airgap, which deploys a registry VM on the cluster. This VM hosts the Kubernetes software components required to deploy and upgrade the Kubernetes cluster.请确保不使用DHCP，因为IP地址需要保持静态。(An AHV network with IPAM is recommended.)

4. 启用后，因此，任何Kubernetes群集部署或升级后，将使用注册表VM中托管的软件。

4. Even after following Airgap instructions, if not able to enable viakarbonctl, what should be done?

Please follow the troubleshooting guide in theSolutionSection.

5. Can Airgap be disabled once enabled?

Disabling Airgap is possible only after removing any existing Karbon clusters that were deployed after Airgap was enabled. Please ensure to remove any Karbon cluster deployed post-airgap enablement and contactNutanix Support有关进一步的步骤。在将来的karbon版本中，预计该过程将记录在最终用户中。

Starting with Karbon 2.0.0, Airgap cannot be disabled as long as there any existing k8 clusters, Airgap, or not.

Troubleshooting Scenarios

Karbon Airgap feature can potentially fail at different stages:

1. Upgrading thekarbon_core和karbon_ui通过LCM暗站点服务器到2.0或更高的组件。

2. Enabling airgap mode (including deploying the Airgap VM).

3. Deployment and upgrade of Karbon clusters and/or host images once Airgap is enabled.

Scenario 1: Karbon upgrade failure via LCM dark site bundle

One of the first steps is to upgrade Karbon to at least 2.0 via the LCM dark site bundle process. If there is a failure at this stage, it is recommended to begin with the investigation on the LCM component. Perform the following basic sanity checks:

1. Confirm that the Prism Central VM(s) can reach the webserver URL and the path provided in the URL from where the dark site bundle was extracted.

2. Confirm that both the LCM dark site bundle and Karbon's LCM dark site bundle were extracted into the same parent directory on the webserver.

3. Confirm that both Nutanix "compatibility" files in the webserver path were replaced with the two compatibility files from the Karbon software download page on the Nutanix Portal.

4. 一旦确认了先前的步骤，请通过LCM和Genesis日志对问题进行故障排除。

   1. genesis.out
      One of the most important logs when it comes to troubleshooting LCM is genesis logs on the Prism Central VM:
      nutanix@PCVM~$ less /home/nutanix/data/logs/genesis.out

   2. lcm_ops.out
      这是模块的清单/更新操作日志。这仅是在充当LCM领导者的Prism Central VM上创建的：
      nutanix@pcvm〜 $ sily/home/nutanix/data/logs/lcm_ops.out

   3. lcm_wget.log

Logs pertaining to downloads from the webserver URL to the cluster:

nutanix@PCVM~$ less /home/nutanix/data/logs/lcm_wget.log

4. lcm_leader (in the case of Prism Central scale-out)
   Thelcm_leadercommand is used to find the Prism Central VM that is the LCM leader. In a Prism Central scale-out setup, the LCM leader is responsible for initiating the upgrade:

nutanix@PCVM~$ lcm_leader

For more scenarios and information, please refer to the following documentation:

https://portal.nutanix.com/page/documents/kbs/details?targetId=kA00e000000Cv1TCAS