DIY NAS: 2026 Edition

- Finding a low-wattage/high-efficiency ATX/SFX PSU is the hardest part. To achieve the advertised efficiency, your Gold-rated PSU needs at least 20% load. I.e. 100W for a 500W PSU. If you are building for low-power, you will need much lower wattage for the PSU to operate at optimal conditions/efficiency. Good luck finding anything under 450W these days.

- Do your math before choosing RAIDX, where X != 1. E.g. the disk cost for 2*16TB RAID1 array is pretty close to the cost of 3*8TB RAID5 array of the same capacity. But future upgrades with RAID1 are much easier and less costly, given that your NAS box will probably have only 4-5 slots. RAIDX make sense if you want to go wild (target NAS capacity >> maximum available single disk capacity).

- If you have not jumped into the "homelab" rabbithole and you only want a NAS and some services, NAS operating systems like TrueNAS are a PITA. Your hardware will be "owned" by the NAS OS, and you will need to jump through hoops to get any other software running. Most of them encourage you to not run anything else on them, except from prepackaged apps from their "store". So, you may want to stick with something more prosaic. E.g. vanilla debian.

- If you are thinking of ZFS/TrueNAS because of the scrubbing functionality, RAID1 + BTRFS also have scrubbing.

- Motherboards from AliExpress save you time. If I could procure a motherboard with 6 SATA ports, at least 2 2.5GbE ports, and an N series CPU from a mainstream vendor, I probably would. But there aren't any such models. If you try to add these features on top of a standard motherboard, you need another round of researching components. Plus, if it is a mini-ITX mobo, you may run out of PCIe slots.

- Motherboards from AliExpress are just fine. I'm not sure why people nag about "reliability" without even anecdotal evidence. If your mobo dies, too bad. But mobos are pretty low in the list of components affecting the safety of your data, with PSU, disks and software being more important.

The problem is that while the tapes are at least 3 times cheaper than HDDs, and you have other additional advantages, e.g. much higher sequential reading/writing speed and much longer storage lifetime of the tape, the tape drives are extremely expensive, at a few thousand $, usually above $3k.

You can find tape drives for obsolete standards at a lower price, but that is not recommended, because in the future you may have a big tape collection and after your drive dies you will no longer find any other compatible drive.

Because the tapes are cheap, there will be a threshold in the amount of data that you store where the huge initial cost of the tape drive will be covered by the savings from buying cheap tapes.

That threshold is currently at a few hundred TB of stored data.

I use an LTO tape drive and I have recovered its cost a long time ago, but I have more than 500 TB of data.

However, only a third of that is actual useful data, because I make 2 copies of each tape, which are stored in different locations. I am so paranoid because it is data that I intend to keep forever and I have destroyed all the other supports on which it was stored, e.g. the books that I have scanned, for lack of storage space. An important purpose of the digitization has been to reduce the need for storage space, besides reducing the access time.

I keep on my PC a database with the content of all tapes, i.e. with all the relevant metadata of all the files that are contained inside the archive files stored on the tapes.

When I need something, I search the database which will give me the location of the desired files as something like "tape 47 file 89" (where "file 89" is a big archive file, typically with a size of many tens of GB). I insert the appropriate tape in the drive and I have a script that will retrieve and expand the corresponding archive file. The access time to a file averages around 1 minute, but then the sequential copying speed is many times higher than with a HDD. Therefore, for something like retrieving a big movie, the tape may be faster overall than a HDD, despite its slow access time.

There are programs that simulate a file system over the tape, allowing you to use your standard file manager to copy or move files between a tape and your SSD. However I do not use such applications, because they reduce a lot the performance that can be achieved by the tape drive. I handle frequently large amounts of data, i.e. the archive files in which I store data on the tapes are typically around 50 GB, so the reduced performance would not be acceptable.