IPMI data for power supply missing

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.

I had a warranty PSU exchange in maybe 30% of my devices over the years. I consider this high enough that I want redundancy for this and would recommend it wherever feasible. In fact, PSUs were the only part except HDs I ever had to replace.

There are other reasons to consider redundant power as well:

• An UPS won't protect you from a failing PSU. This might lead to broken filesystems etc, with unnecessary high recovery times.
• You can connect your device to two or more different breaker circuits. Depending on your environment, you might not reach your server room fast enough before the UPS runs out of juice if a breaker trips. With redundant PSUs, hopefully the second circuit will last.
• There are devices you cannot easily keep redundant, like switches etc. Here, a second PSU is mandatory, IMHO.