I have 6 servers both with 2 power supplies attached to an UPS. I want to add 4 more servers but the UPS is full and due to budget restriction I couldn't buy a new one for months. The 6 + 4 new servers are running essential services (high uptime required).
Questions :
- What is the power supply failure rate or how many failure have you experienced so far ?
- If the failure rate is low, how safe is it to use only one psu per server and keep the redundant one as backup if the first one fails ?
- Does it make sense to connect one psu to the UPS and the second one to a normal plug ?
Best Answer
If all the servers have redundant PSUs (), you can plug just enough PSUs into the UPs and rest into the main powergrid. If you have 10 servers, with dual PSUs each (which makes 20 PSUs to plug into the power), you can simply plug only one of them into the UPS (so you would only take up 10 sockets in the UPS's PDB) - in case of power failure, the UPS will hold the servers up.
However, this does not cancel the previous comments about a UPS not being the ultimate answer to power failures.