NaibofTabr

Yeah, it’s one of the best reasons to actually RTFM: “How does the guy that designed this think it works? What did they intend for it to do?”

I also find it’s useful when I’m vague on the specifics, especially with network protocols. I might be expecting it to do something and then find out, oh, this doesn’t solve that problem, I’m in the wrong config file.

Well the “critical/irreplaceable” qualifier is kind of important - that’s why I specified it. It’s up to you to decide what that means for your data and risk tolerance.

For everything that I consider irreplaceable, I’m not comfortable with anything less than 100% duplication on the live system, and also an external offline backup. Even with enterprise-grade hardware, I don’t trust storage devices, they’re all destined to fail. Storage is the most important part of a data server, and should be treated like it is constantly trying to light itself on fire, like a library with wooden shelves lit with torches. All the other components are just as unreliable, but more expendable.

Admittedly, when you account for hot standby drives, the cost is that my storage availability is only 40%. A 16TB storage pool is in fact 5x 8TB drives: 2 mirrored pairs and 1 standby. On the plus side, thanks to ZFS and TrueNAS those drives can be whatever, no need to worry about RAID considerations for matched drives. SAS or SATA? who cares? They can even be different speeds, ZFS will compensate. Buy whatever is the right size for the pool, let the system deal with the other issues.

Can you put a price on stability? longevity? peace of mind?

The server hardware is all old repurposed stuff - a desktop build from 2013, secondhand data center surplus, refurbished/used drives, none of it’s worth much and almost all of it is well past end of life, any part of it could fail without warning at any moment. It doesn’t matter, it is highly reliable because the redundancies have redundancies, including the boot drives. Trying to squeeze every bit of value out of the hardware is a losing game because it’s basically worthless anyway, but the same would be true if it were all new top-of-the-line gear. The hardware is expendable, the data is not. Buy more cheap hardware, plan for it to explode, learn how to build stable, recoverable systems.

Used data center drives are great for a home lab. They’re built like tanks for hundreds of thousands of hours of constant operation. Unless you’re running a business hosting a bunch of public-facing websites out of your garage, you don’t have that kind of workload (and if you are doing that you should just be buying new drives anyway and writing them off as a business expense).

Data center drives get replaced when they hit a ceiling of operating hours, with no actual faults, or if they experience any minor faults (it’s a business expense - drives are consumables - data centers have storage rooms of spares sitting around, they just replace them).

Any competent reseller should be able to give you a SMART report, and that should tell you if there are any major issues (generally they don’t get resold if there are, nobody will buy them). If the seller won’t give you a SMART report then obviously don’t buy, they’re either a scammer or incompetent.

If your array redundancy is set up properly then there’s no reason to be “scared” or trust in “good luck”. Assume luck will be bad. Mirror every storage device that has critical/irreplaceable data on it, and have at least one hot standby drive in every pool. Don’t bother with complicated striping schemes to try and scrape a little more storage space out of your drives, that’s dumb. One-to-one mirroring for every drive. Storage drives are consumables. They will fail, not if but when, even if you only buy new. Learn to read a SMART report. Enjoy quality hardware with no real problems at low prices.

Computer networking is basically a completely different field from operating systems and programming, though obviously some of the concepts are relevant. Turns out plugging these things into each other so that they can share information in a useful way is kind of difficult. A lot of very smart people have been working on it for almost 70 years, and frankly it’s still a fucking mess, so don’t feel bad if you feel a little lost.

Starting with the basics is the right instinct, in my opinion. Start with the OSI model:

https://jakarta.telkomuniversity.ac.id/7-osi-layer-the-building-blocks-of-networking/

https://www.geeksforgeeks.org/computer-networks/osi-model-analogy-osi-7-layers-explained/

This helps to break down the actual functioning of the network into logical steps. It’s very helpful when you’re trying to visualize the operation of some of the more abstract bits of the technology stack (like TCP/UDP), and when you’re trying to think through what piece of it might be causing your problem in the moment (the router is on and the cables are plugged in, why is there no connection?). It’s a map that can help you when you’re lost. It’s also a guide to how a lot of people who work on networking technology think, so it can help you understand how things are supposed to work.

Beyond that, Professor Messer is a great resource: https://www.professormesser.com/

If you feel reasonably confident with computer hardware components and various types of cable connectors, you can probably skip the A+ part and go straight into Network+. Because you’re doing this as a home hobbyist (not for the actual certification), I recommend just listening to the courses like you would a podcast. Don’t try to memorize or fully understand everything, just use it to get a grasp of the terminology and purpose of the various pieces.

I also recommend taking on a project to gain experience. Implenting PiHole https://pi-hole.net/ for your home network will cover routing, DHCP and DNS, plus you can do it with a Docker container.