phosphor-regulators/docs/multiple_chassis.md

1 # Multiple Chassis
5 A BMC-based system can contain one or more chassis. A chassis is typically a
9 A chassis can be stand-alone, such as a tower or desktop. A chassis can also be
12 For the `phosphor-regulators` application, the term "single chassis system"
13 means the system type has a maximum configuration of one chassis. If the system
14 type has a maximum configuration of multiple chassis, then it is considered a
15 "multiple chassis system" even if the current system only contains one chassis.
18 does not support powering on/off individual chassis independent of the rest of
21 ## Defining the chassis in a system
24 more [chassis](config_file/chassis.md) objects. Each chassis object corresponds
25 to a physical chassis in the system.
27 ## Differences between single and multiple chassis systems
29 ### System and chassis power state
31 In a single chassis system, the system and chassis power state are identical.
34 In a multiple chassis system, each chassis has its own power state. Even if the
35 system is on, an individual chassis may be off. This can occur if that chassis
38 See [Chassis Status](../phosphor-power-sequencer/docs/chassis_status.md) for
43 In a single chassis system, regulator configuration is always performed on the
44 chassis.
46 In a multiple chassis system, regulator configuration will only be performed on
47 chassis with the proper status. For example, a chassis that is missing or has no
54 In a single chassis system, regulator monitoring is always performed on the
55 chassis.
57 In a multiple chassis system, regulator monitoring will only be performed on
58 chassis with the proper status. For example, a chassis that is missing or has no