NCC is a framework that serves as the engine for the Nutanix Cluster Health. It consists of various modules and plugins. The modules are groups of plugins that correspond to a specific test category. NCC can be run as long as individual nodes are up, regardless of cluster state. The scripts run standard commands against the cluster or the nodes, depending on the type of information being retrieved.
The philosophy of NCC is for each plugin to function as a test that can be interpreted in most cases as a clear pass/fail. In addition to [PASS] and [FAIL], there are two additional results. Warning [WARN] is used when a value returned is unexpected by the check and the value needs to be investigated. Informational [INFO] is used so that a plugin can return a value that cannot be evaluated as pass/fail and does not require any investigation.
NCC checks fall into two non-disjoint sets today: batch-run manual NCC checks, and NCC checks that drive Prism Health page (image below). Not all the NCC tests are part of Prism 4.0 UI. There is a sub-set that are not good candidates to be part of cluster health for various reasons and can only be run by cli. The important thing to remember is that just downloading the new NCC release you are adding additional and improved health checks to you Nutanix cluster.
(Click on the image to enlarge)
Download NCC 1.1
- Download the tarball onto any CVM in the cluster.
- The directory to which you copy the tarball should exist on all nodes in the cluster (/home/nutanix is suggested).
- The directory should be owned by whatever accounts will use the NCC utility.
- Extract tarball:
$ tar xvmf –recursive-unlink
- recursive-unlink option is needed to ensure old installs are completely removed.
- Execute the install script (provide the tarball name if it has been moved or renamed).
$ ./ncc/bin/install.sh [-f ]
- Check the output of this command for any error messages. If it runs to success, you will see the following output
- Optionally, source the bash tab-completion script.
$ source ~/ncc/ncc_completion.bash
- Currently completion only works for modules and plugins (does not support flags).
- To ensure tab completion works on subsequent logins, add the line to ~/.bashrc.
NCC’s release cycle is independent from the NOS release cycle. This enables Nutanix Engineering to develop new plugins and modules without creating a dependency on a particular NOS release. The release frequency is approximately one month, but it can vary depending on the amount of work that needs to be done to develop new plugins and modules.
You can find more information on NCC at the Nutanix Portal (here)
This article was first published by Andre Leibovici (@andreleibovici) at myvirtualcloud.net.