Recording Power connections

[sscotter]

Hi,
I'm struggling to understand how best way to record the power connections between our servers and PDU rails in the racks.

Environment
I have three racks across two datacentres. Each rack has two separate PDUs which (as I understand it) and feed by two different sources and protected by two different diesel generators in the event of a problem. ie, I have six PDU's in total.

I've tried the following strategies

Strategy 1
I created two Power Panels, one for each datacentre.
I then created six Power Feeds to represent the PDUs in the racks and assigned those to the correct Power Panel

• DC 1 - Rack A - Left PDU
• DC 1 - Rack A - Right PDU
• DC 1 - Rack B - Left PDU
• DC 1 - Rack B - Right PDU
• DC 2 - Rack C - Left PDU
• DC 2 - Rack C - Right PDU

This allowed me to record that (for example) Server A in DC 1 has PSU1 connected to DC 1 - Rack A - Left PDU and PSU2 connected to DC 1 - Rack A - Right PDU. However, when it came time to record Server B's (also in Rack A) power connectivity, both DC 1 - Rack A - Left PDU, and DC 1 - Rack A - Right PDU where greyed out.

At this point it dawned on me that maybe Power Feeds represent the individual plugs on the PDU.

Strategy 2
Deleted all Power Panels and Power Feeds and started again.
Created four Power Panels, two for each datacentre.

• Power Panel DC 1 - Left PDUs
• Power Panel DC 1 - Right PDUs
• Power Panel DC 2 - Left PDUs
• Power Panel DC 2 - Right PDUs

I then went to create 16 Power Feeds for Power Panel DC 1 - Left PDUs, with the intention of giving them names such as Rack A - Left PDU - Port [0-15] and it literally created ONE Power feed named Rack A - Left PDU - Port [0-15], not 16 power feeds named Rack A - Left PDU - Port 0,Rack A - Left PDU - Port 1 etc. ie, the Add a new power feed page doesn't support bulk creation like most creation pages seem to in Netbox.

Manually creating the following four ports allowed me to record Server A and Server B's power connections. Result!, so now I just need to quickly and accurately create the induvial Power Feeds

• Rack A - Left PDU - Port 1
• Rack A - Right PDU - Port 1
• Rack A - Left PDU - Port 2
• Rack A - Right PDU - Port 2

Strategy 3
To save myself to finger effort I thought I'd import a CSV with the relevant information PDU names in so they're created consistently and less prone to typos. Using the following CSV to import Power Feeds...

site,name,power_panel,rack,status,type,supply,voltage,amperage,phase,max_utilization
Site A,Rack A - Left PDU - Port 1,Power Panel DC 1 - Left PDUs,r203,active,primary,ac,240,20,single-phase,80

... I get the following error...
Record 1 rack: Object not found: R203.

The rack name is definitely R203. The slug is r203 and the id of the rack is 23. Using either the slug or the id in the CSV results in exactly the same error Record 1 rack: Object not found: r203 or Record 1 rack: Object not found: 23.

It's worth pointing out I don't know why site is a required attribute when bulk importing power feeds because it is not a field asked for at all (required or not) when creating a power feed manually.

Am I doing something wrong (or even stupid) or does netbox have a bug in the import of power feeds?

Cheers

Steve

[candlerb]

At this point it dawned on me that maybe Power Feeds represent the individual plugs on the PDU.

They represent the individual feeds into the PDU. Think of a power feed as a circuit breaker that supplies power to you. A power panel is just a grouping where power feeds are located together.

In a typical data centre, there would be two power feeds into each rack - an A and B feed - and Netbox allows each power feed to be optionally associated with a rack (it's mandatory to associate it with a power panel though). Then you'd connect each power feed into a PDU device (to its power port), and then connect the power outlets on the PDU device to the power ports of the other devices in the rack.

I don't fully understand what you've modelled, because you mention PDUs but haven't said how you've connected them. Normally a PDU would have one power port (inlet) and multiple power outlets linked internally to that power port, and then the power outlets would connect to power ports on your servers. (For a similar recent case see #12902)

For your CSV: to import power feeds, if you want to associate them with a rack, you need to use the name of the rack. It doesn't matter if the slug is r203 or the database id is 23, it must have name of (say) "R203", and I presume must be in the same site. (Slugs are mostly unused in Netbox, although there are cases you can use them for query filtering in the REST API). Similarly, the name of a rack is only unique within a Location (a.k.a. "rack group" originally), so you may need to specify both the Location Name and the Rack Name to identify it uniquely.

It's worth pointing out I don't know why site is a required attribute when bulk importing power feeds

I believe it's because the name of a power panel is only unique within a site, so the combination of (site_name, power_panel_name) is needed to identify it.

Aside: I've been trying to document the power features in Netbox in more detail, especially with regards how it calculates overall power utilization from individual device power draw. The gory details are in #12837.

[CvR42]

A bit late but this seems a reasonable follow-up question:

Power feeds as something that has a circuit breaker makes absolute sense to me, but then why is there the restriction to allow only one connection to a power feed? Real-world wiring normally doesn't have that restriction. Are we supposed to split the power feed explicitly with some kind of PDU that feeds the PDUs?