The minimal downtime upgrade process (also referred to as rolling upgrade) significantly reduces the amount of time your system is offline while you are upgrading to the latest version. The degree to which your BIG-IQ system and DCD cluster can maintain complete online function during upgrade depends on which BIG-IP services you manage, and what kind of data you collect.
The following upgrade process to BIG-IQ Centralized management version 6.1.0 is for system setups that currently have version 6.0.x installed, and include a data collection device cluster with at least three devices. If your system is not currently running version 6.0.x and does not include a data collection device cluster with three or more devices, refer to Which BIG-IQ setups support an upgrade to version 6.1.0?.
To ensure that your upgrade goes smoothly, F5 recommends that you perform a few system checks. Perform this test at least a day or so before you upgrade in case you discover any issues that take longer than expected to resolve. Going through this list ahead of time gives you a chance to resolve any issues before the clock is ticking on your upgrade window.