DL series servers - power distribution with dual PS

[robert switzer_1]

I am trying to understand how dual PS and PDU work. I have read some HP docs but not found a clear explanation.

As a simple example, I have a server with dual power and two 10 A circuits.

Each PS is connected to a different 10 A PDU. When viewing current draw on the PDU, I see 2 A being used when the server is running and 5 A when the server boots up.

If one PDU or PS goes away, does the server now pull 4 A in normal run and now 10 A at boot up on the single PS/PDU?

I don't think it pulls that much but haven't had the ability to test PS/PDU scenerios.

[TTr]

> If one PDU or PS goes away, does the server now pull 4 A in normal run and now 10 A at boot up on the single PS/PDU?

Yes that's exactly what will happen. So each PDU must be able to supply double the current at any time if the other PDU goes down. It is a killer if you have dual feeds with dual UPSrooms and dual generators. Your UPSes and generators must never run over 50% load.