Magnetic Media

It’s one of the great mysteries of computing, how somehow in the Year Of OLlama 2026, tape remains the god of cheap storage. A while back [Ben Pettis] recounted his experience setting up an LTO-5 tape drive in his homelab, an experience which only becomes more relevant as hard drive prices stay high.

LTO-5 is already well out of date in the professional world, after all– a new server install would be debating the merits of LTO-9 versus LTO-10, but for the homelab it’s a matter of what’s affordable on the used market with decently-sized cartridges. If you can live with 1.5 TB of uncompressed data on a roughly palm-sized Linear Tape, Open cartridge then LTO-5 could be good enough. Yes, the tapes are advertized as 3GB, but that’s assuming a 2:1 compression ratio on the data, which you’re not likely to get on the photos and video that make up much of a data horder’s storage. That’s one thing [Ben] was quick to clear up for us. He also detailed his adventures with the cheaper-to-buy fiber channel model of drive.

The label would have you believe this box stores 30 TB.

Tape drives usually come with an SAS or fiber channel interface– fiber channel being, you guessed it, an optical solution unlike the SCSI-like SAS connection you may be familiar with for block storage devices. With a PCIe adapter it’s not hard to set up, provided you get the cables the right way around! That’s another detail we’re glad [Ben] shared so we can find it again if we have the same problem: with no switch in the circuit, you need a crossover cable to bring TX to RX. Which is obvious in retrospect, but obscure to those of us just learning about the standard.

The advantage, as [Ben] makes clear and everyone has always known is simply price. As of this writing, diskprices.com has 16$/TB as the lowest cost, while [Ben] was able to pick up lightly-used tapes on eBay for only 2$/TB. If you have a lot of data, those savings amortize the drive costs relatively quickly, since a used drive like [Ben]’s can be had for a few hundred bucks.

Is it the ultimate solution for our data storage woes? That depends on your needs, but perhaps not considering we get as many tips on storing data on reel-to-reel as we do on LTO. We even saw a tape-loading robot repurposed to serve bar one time.

The use of magnetic tape and other removable magnetic media is now on the wane, leading to scarcity in some cases where manufacture has ceased. Is it possible to produce new magnetic tape if you don’t happen to own a tape factory? [Nina Kallnina] took the effort to find out.

It’s probably one of those pieces of common knowledge, that magnetic media use iron oxides on their surface, which is the same as rust. But the reality is somewhat more complex, as there is more than one iron oxide. We follow [Nina] through this voyage of discovery in a Mastodon thread, as she tries first iron filings, the rust, and finally pure samples of the two iron oxides Fe3O4 and Fe2O3. She eventually achieves a working tape with a mixture of Fe2O3 and iron powder, though its performance doesn’t match manufactured tape. It turns out that there are two allotropes of Fe2O3, and she leaves us as she’s trying to make the one with better magnetic properties.

These results look promising, and while there is evidently a very long way to go before a home-made magnetic coating could replicate the exacting demands of for example a hard drive platter it’s evident that there is something in pursuing this path.

This may be the first time we’ve seen tape manufacture, but we’ve certainly seen extreme measures taken to rejuvenate old tapes.