Selfhosted

I have a bit of a dilemma with my DIY NAS rig.

Does your setup have any way to do noise insulation? I suspect the answer is no but figured I'd throw it out there, surprisingly noise insulation helps more than you'd think. I have a bunch of drives inside a desktop case with insulation panels built in and the drives themselves are in there with rubber anti vibration screws/mounts. Barely ever hear anything from the drives (granted my WD Reds are probably quieter than your current Seagates).

Just something to think on whether it's an option for your current NAS rig or a future configuration.

The usual trick is hdparm I guess? For me with a 8 disk raidz2 pool I found that playing a movie from that might put it to sleep between reads, because the longest timeout is a bit short. I've been using hd-idle with a 30 minuten timeout because of that for quite a few years already which has worked quite nice for me.

The only issue I've run into is that smart data reads count as activity, so make sure that any smart data software has a long timeout between reads and is configured to not wake disks.

Putting drives to sleep reduces their lifespan? I thought it was some calculus involved where if they were offline for long enough to offset the cost of the spinup during a time period it was fine. Either way I have an unraid server with 6 disks being put to sleep after 4 hours inactivity and been running that for years. Have had to replace 2 pre owned drives and 1 new WD red that was under warranty in several years.

Why don't you buy a different enclosure for the drives? I have a Fractal Designs Define 6 and I dont hear any of my drives even sitting a foot away from it. The case cost me less than a single 8TB drive, and can hold around 12 3.5" drives, so it seems to be the most economical solution over running your drives into the ground by having them spin up and spin down regularly.

I used to do this. My HDD were used only for the daily backup and nothing else. I had a cronjob sending them to sleep ten minutes after the backups (they usually took the same time). I had them in a ZFS pool and ZFS didn't interfere with the sleep.

Using the HDD (like opening a directory on them or the like) will spin them up, so besides a little lag after the sleep, and the reduced lifespan, it won't harm your system.

There's also a setting where they go to sleep by themselves after not being used for x minutes, but that never really worked for me.

No idea if the passthrough will change anything but I'd just try what works. I think the command was hdparm but I'm not sure anymore.

First of all, a NAS VM is generally considered a bad idea that has been discussed before so I won't repeat it here.

Anything using those drives is going to keep them awake. Usually, NAS software runs background tasks, as does proxmox. You'll have to identify and schedule them to shut down during sleep hours.

But that's going to be a huge pain, because eventually you'll find it's gone to sleep when you haven't, and you want access. I'd see if you could configure proxmox to suspend the VMs and put the whole thing to sleep when you push the power button.

I've put drives into standby mode with the gnome disks GUI tool on my regular desktop when they were being noisy and I wanted some peace for a while. If the drive was mounted before I put it to sleep, trying to access something on the disk will cause it to spin back up.

Don't you want to turn off the whole NAS? Of you don't have the disks spinning, the NAS is probably useless.

Insulation.

Or replace the drives.