Power Algorithm
Gathering power metrics requires a cluster with:
- ONTAP versions 9.6+
- REST enabled, even when using the ZAPI collector. After granting REST permissions, restart Harvest.
REST is required because it is the only way to collect chassis field-replaceable-unit (FRU) information via the
REST API /api/private/cli/system/chassis/fru.
How does Harvest calculate cluster power?¶
Cluster power is the sum of a cluster's node(s) power + the sum of attached disk shelve(s) power.
Redundant power supplies (PSU) load-share the total load. With n PSUs, each PSU does roughly (1/n) the work (the actual amount is slightly more than a single PSU due to additional fans.)
Node power¶
Node power is calculated by collecting power supply unit (PSU) power, as reported by REST
/api/private/cli/system/environment/sensors or by ZAPI environment-sensors-get-iter.
When a power supply is shared between controllers, the PSU's power will be evenly divided across the controllers due to load-sharing.
For example:
- FAS2750 models have two power supplies that power both controllers. Each PSU is shared between the two controllers.
- A800 models have four power supplies.
PSU1andPSU2powerController1andPSU3andPSU4powerController2. Each PSU provides power to a single controller.
Harvest determines whether a PSU is shared between controllers by consulting the connected_nodes of each PSU,
as reported by ONTAP via /api/private/cli/system/chassis/fru
Disk shelf power¶
Disk shelf power is calculated by collecting psu.power_drawn, as reported by REST, via
/api/storage/shelves or sensor-reading, as reported by ZAPI storage-shelf-info-get-iter.
The power for embedded shelves is ignored, since that power is already accounted for in the controller's power draw.
Examples¶
FAS2750¶
# Power Metrics for 10.61.183.200
## ONTAP version NetApp Release 9.8P16: Fri Dec 02 02:05:05 UTC 2022
## Nodes
system show
Node | Model | SerialNumber
----------------------+---------+---------------
cie-na2750-g1344-01 | FAS2750 | 621841000123
cie-na2750-g1344-02 | FAS2750 | 621841000124
## Chassis
system chassis fru show
ChassisId | Name | Fru | Type | Status | NumNodes | ConnectedNodes
---------------+-----------------+---------------------+------------+--------+----------+-------------------------------------------
021827030435 | 621841000123 | cie-na2750-g1344-01 | controller | ok | 1 | cie-na2750-g1344-01
021827030435 | 621841000124 | cie-na2750-g1344-02 | controller | ok | 1 | cie-na2750-g1344-02
021827030435 | PSQ094182201794 | PSU2 FRU | psu | ok | 2 | cie-na2750-g1344-02, cie-na2750-g1344-01
021827030435 | PSQ094182201797 | PSU1 FRU | psu | ok | 2 | cie-na2750-g1344-02, cie-na2750-g1344-01
## Sensors
system environment sensors show
(filtered by power, voltage, current)
Node | Name | Type | State | Value | Units
----------------------+---------------+---------+--------+-------+--------
cie-na2750-g1344-01 | PSU1 12V Curr | current | normal | 9920 | mA
cie-na2750-g1344-01 | PSU1 12V | voltage | normal | 12180 | mV
cie-na2750-g1344-01 | PSU1 5V Curr | current | normal | 4490 | mA
cie-na2750-g1344-01 | PSU1 5V | voltage | normal | 5110 | mV
cie-na2750-g1344-01 | PSU2 12V Curr | current | normal | 9140 | mA
cie-na2750-g1344-01 | PSU2 12V | voltage | normal | 12100 | mV
cie-na2750-g1344-01 | PSU2 5V Curr | current | normal | 4880 | mA
cie-na2750-g1344-01 | PSU2 5V | voltage | normal | 5070 | mV
cie-na2750-g1344-02 | PSU1 12V Curr | current | normal | 9920 | mA
cie-na2750-g1344-02 | PSU1 12V | voltage | normal | 12180 | mV
cie-na2750-g1344-02 | PSU1 5V Curr | current | normal | 4330 | mA
cie-na2750-g1344-02 | PSU1 5V | voltage | normal | 5110 | mV
cie-na2750-g1344-02 | PSU2 12V Curr | current | normal | 9170 | mA
cie-na2750-g1344-02 | PSU2 12V | voltage | normal | 12100 | mV
cie-na2750-g1344-02 | PSU2 5V Curr | current | normal | 4720 | mA
cie-na2750-g1344-02 | PSU2 5V | voltage | normal | 5070 | mV
## Shelf PSUs
storage shelf show
Shelf | ProductId | ModuleType | PSUId | PSUIsEnabled | PSUPowerDrawn | Embedded
------+-----------+------------+-------+--------------+---------------+---------
1.0 | DS224-12 | iom12e | 1,2 | true,true | 1397,1318 | true
### Controller Power From Sum(InVoltage * InCurrent)/NumNodes
Power: 256W
AFF A800¶
# Power Metrics for 10.61.124.110
## ONTAP version NetApp Release 9.13.1P1: Tue Jul 25 10:19:28 UTC 2023
## Nodes
system show
Node | Model | SerialNumber
----------+----------+-------------
a800-1-01 | AFF-A800 | 941825000071
a800-1-02 | AFF-A800 | 941825000072
## Chassis
system chassis fru show
ChassisId | Name | Fru | Type | Status | NumNodes | ConnectedNodes
----------------+----------------+-----------+------------+--------+----------+---------------
SHFFG1826000154 | 941825000071 | a800-1-01 | controller | ok | 1 | a800-1-01
SHFFG1826000154 | 941825000072 | a800-1-02 | controller | ok | 1 | a800-1-02
SHFFG1826000154 | EEQT1822002800 | PSU1 FRU | psu | ok | 1 | a800-1-02
SHFFG1826000154 | EEQT1822002804 | PSU2 FRU | psu | ok | 1 | a800-1-02
SHFFG1826000154 | EEQT1822002805 | PSU2 FRU | psu | ok | 1 | a800-1-01
SHFFG1826000154 | EEQT1822002806 | PSU1 FRU | psu | ok | 1 | a800-1-01
## Sensors
system environment sensors show
(filtered by power, voltage, current)
Node | Name | Type | State | Value | Units
----------+---------------+---------+--------+-------+------
a800-1-01 | PSU1 Power In | unknown | normal | 376 | W
a800-1-01 | PSU2 Power In | unknown | normal | 411 | W
a800-1-02 | PSU1 Power In | unknown | normal | 383 | W
a800-1-02 | PSU2 Power In | unknown | normal | 433 | W
## Shelf PSUs
storage shelf show
Shelf | ProductId | ModuleType | PSUId | PSUIsEnabled | PSUPowerDrawn | Embedded
------+-------------+------------+-------+--------------+---------------+---------
1.0 | FS4483PSM3E | psm3e | | | | true
### Controller Power From Sum(InPower sensors)
Power: 1603W