Measured load
The measured peak power reported by the devices through an external system integration during a period of 30 days (configurable). When using the power tool tip on servers, the measured data shown (if any) will be coming from the Data Center: IT Optimize and is not part of the measured load shown at rack level. The measured data at that level will be coming from associated rack PDUs discovered by Data Center Expert.
Estimated load
The load of all equipment in the rack even if the equipment has not been connected to a rack PDU (often the manufacturer's nameplate value), unless the equipment has been marked as not being connected (Power properties setting, Exclude rack's load from power calculations).
If a server is connected to 2 UPS units, the estimated load on each UPS is 1/2 the total estimated load, and the remaining 1/2 is shown as failover load. In a typical scenario, it is expected that each server loads the 2 UPS units evenly, but in case one of them is turned off, the other one will have to carry the full load and the load "fails over" to that UPS. See also potential failover Load.
Tip
If the load seems very high, check that the estimated load on each server is realistic. If the load still seems very high, you can improve this by supplying more information, such as how the server is connected to the rack PDUs, or by supplying measured (peak) power data for all rack PDUs in the rack.
If the load is red, it exceeds the supported load. See here for troubleshooting tips.
Potential failover load
The additional load in case the other power feed is turned off. For example, if the A-Feed UPS was turned off, then the B-Feed UPS has to carry the full load, and so should the Rack PDU breakers, etc.
If the load is red, it exceeds the supported load. See here for troubleshooting tips.
Redundancy
The rack's redundancy level.
Definition: The provision of multiple interchangeable components to perform a single function in order to cope with failures and errors, e.g. the setup of more power supplies to reduce the risk of failure of the entire system in case one of them fails. For information about configuring power connections, see here.
- N: No redundancy.
- N+1: One UPS with one redundant power module (also referred to as internal redundancy in the UPS Power properties page). If the UPS fails, there is no redundant UPS serving as backup, but if one of the power modules inside the UPS fails, the redundant module ensures that the UPS still has full capacity. In other words, the spare power is at least equal to the capacity of one system module.
- 2N: Two UPS where one serves as backup for the other in case one of them fails. One UPS is referred to as A feed and the other as B feed.
- 2N+1: This is a combination of N+1 and 2N for combined external and internal redundancy, both one redundant UPS and one redundant power module inside both UPS.
- DN: This is a combination of D (distribution redundancy) and N (above). For this type of redundancy, the power distribution is redundant but there is no redundancy on the UPS level. Therefore, you are still vulnerable to failure on the power supply.
- DN+1: This is a combination of D (distribution redundancy) and N+1 (above). For this type of redundancy, the power distribution is redundant and there is internal redundancy on the UPS level (one UPS with one redundant power module).
Largest possible server
The maximum load that a potential new server is allowed to add to the rack (without exceeding the allowed average power draw per phase).
