I use BTRFS w/ RAID 1 (mirror) with two drives (both 8TB), because that’s all I’ve needed so far. If I had four, I’d probably do to separate RAID 1 pairs and combine them into a logical volume, instead of the typical RAID 10 setup where blocks are striped across mirrored sets.

RAID 5 makes sense if you really want the extra capacity and are willing to take on a little more risk of cascading failure when resilvering a new drive.

ZFS is also a great choice, I just went w/ BTRFS because it’s natively supported by my OS (openSUSE Leap) with snapshots and rollbacks. I technically only need that for my root FS (SSD), but I figured I might as well use the same filesystem for the RAID array as well.

Here’s what I’d do:

1. 4x 16TB HDDs either in a RAID 10 or two RAID 1 pairs in one logical volume - total space is 32TB
2. 500GB SSD -> boot drive and maybe disk cache
3. 8TB HDD - load w/ critical data and store at work as an off-site backup, and do this a few times/year; the 4x HDDs are for bulk, recoverable data

That said, RAID 5 is a great option as well, as long as you’re comfortable with the (relatively unlikely) risk of losing the whole array. If you have decent backups, having an extra 16TB could be worth the risk.

That video is about hardware RAID. Software RAID is still alive and well (e.g. mdadm).

I personally use BTRFS w/ RAID 1, and if I had OP’s setup, I’d probably do RAID 10. Just don’t use RAID 5/6 w/ BTRFS.

ZFS isn’t the only sane option.

Watchtower

Glad it works for you.

Automatic updates of software with potential breaking changes scares me. I’m not familiar with watchtower, since I don’t use it or anything like it, but I have several services that I don’t use very often, but would suck if they silently stopped working properly.

When I think of a service, I think of something like Nextcloud, Immich, etc, even if they consist of multiple containers. For example, I have a separate containers for libre office online and Nextcloud, but I upgrade them together. I don’t want automated upgrades of either because I never know if future builds will be compatible. So I go update things when I remember, but I make sure everything works after.

That said, it seems watchtower can be used to merely notify, so maybe I’ll use it for that. I certainly want to be around for any automatic updates though.

Automatically upgrading docker images sounds like a recipe for disaster because:

• could pull down change that requires manual intervention, so things “randomly” break
• docker holds on to everything, so you’d need to prune old images or you’ll eventually run out of disk space; if a container is stopped, your prune would make it unbootable (good luck if the newer images are incompatible with when it last ran)

That’s why I refuse to automate updates. I sometimes go weeks or months between using a given service, so I’d rather use vulnerable containers than have to go fix it when I need it.

I run OS updates every month or two, and honestly I’d be okay automating those. I run docker pulls every few months, and there’s no way I’d automate that.

Oh yeah, as a hobby, it’s absolutely fun. I like tinkering with all kinds of things.

My point was to just be careful since it’s not necessarily going to be worth the expense and time.

I’ve been considering getting a breaker-level power monitor to watch for spikes. It’s a bit more expensive (hundreds of dollars), but it measures the types of things I’m interested in. My kid flipped on our gutter heaters (I never use them) and shot our electricity bill to the moon for a couple months until I noticed. If I had a home energy monitor, I would’ve noticed a crazy energy spike and that might have paid for itself.

Cool!

Just be cautious that you don’t over-optimize for power. I ran around my house w/ a Kill-a-watt meter checking everything and made some tweaks, and I still don’t think it has paid for itself since power costs are so low here ($0.12-0.13/kWh, so 10Wh 24/7 < $1/month), and some of the things I tried doing made my life kinda suck. So I backed off a bit and found a good middleground where I got 80% of the benefit w/o any real compromises.

For example, here’s what I ended up with:

• put desktop to sleep - power draw is negligible, and I don’t need to keep typing my FDE password to use it
• “upgraded” NAS from old 2009 HW to my old gaming PC HW (1st gen Ryzen) - cut power draw in half, but I had to buy some RAM; will take years to pay off w/ electricity savings, but it has much better performance in the meantime
• turn off work laptop - was drawing ~20W; I WFH MThF, so I leave it on Th night for convenience, but have it sleep M-W and turn it off Friday

I could probably cut a bit more if I really try, but that would be annoying.