Couchbase Server 6.5.1 introduces a standardized approach for non-root installation and upgrade of rpm packages, allowing users to manage Couchbase Server without root access. The article outlines best practices for both installing and upgrading the server, highlighting the use of a new installer, cb-non-package-installer, to facilitate these processes. Key steps include disabling Transparent Huge Pages (THP), configuring kernel swappiness, and setting appropriate ulimits for optimal performance. The text provides a detailed walkthrough for deploying a three-node Couchbase cluster as a non-root user, using a specific setup with directories for server and data storage. It also covers the process of upgrading from Couchbase Server 6.0.4 to 6.5.1, involving steps like graceful failover, server shutdown, upgrade, and subsequent rebalancing of the cluster. Essential pre-requisites are emphasized for both installation and upgrade to ensure a smooth transition, and the article concludes with verifying the server version post-upgrade.