I believe this is a slightly controversial topic, at least from what I have gathered so far. Some say its best to leave the server on to spare the life time of the spinning rust. Other seem to prefer to save power and boot the server off each night. So wanted to chip in and hear what folks here do and why do what you do.
Bonus question; Do you guys have a UPS? Is it a must have for a homelab, or does it just depend on the usecase?
No. Yes. Kind of.
My home setup is three ProLiant towers in a ProxMox cluster. One box handles all-the-time stuff like OpenWRT, file server, email, backups, and - crucially - Home Assistant and is UPS protected because of how important it’s jobs are. The other two are powered up based on energy costs; Home Assistant turns them on for the cheapest six hours of the day or when energy costs are negative and they perform intensive things like sailing the high seas, preemptive video transcoding, BOINC workloads and such. The other boxes in the photo are also on all the time basically being used as disk enclosures for the file server and they are full of mismatched hard disks that spend virtually all their time asleep. At rest the whole setup pulls about 35-40W.