They are the great unknowns. Little exciting, almost belonging to another era. Cassettes come to more, it could be said. They are the LTO (Linear Tape-Open) tapes, well known among companies for their need to store huge amounts of data, and little by little the great discovery of mass storage enthusiasts.
Its advantages are obvious: the cost per terabyte is (at least) about three times lower than that of hard disks, and also the longevity of these tapes is enormous: between 25 and 35 years, compared to the 3-5 years that they usually guarantee. the hard drives. Let’s talk about the advantages and disadvantages of a storage medium that is beginning to gain ground among end users.
What are LTO tapes
LTO tapes (for Linear Tape-Open) with a magnetic storage medium that were developed in the late 1990s as an open alternative to proprietary systems that had appeared. The so-called LTO Consortium is controlled by HP, IBM and Quantum, which are the great champions of this technology that is very present in companies.
The standard format for these tapes is called Ultrium, but the curious thing is that the LTO specification is constantly advancing: every two or three years a new generation appears. We are currently in the ninth, known as LTO-9, although most available tapes and drives still take advantage of the eighth generation (LTO-8) which debuted in December 2017.
With each generation, it gains especially in native storage capacity and writing speed. From the 100 GB and 20 MB/s of transfer of the LTO-1 tapes of 2000 we have passed to the 12 TB and 360 MB/s of LTO-8 and the 18 TB and 400 MB/s of LTO-9 (already close to to SATA SSD drives).
A curiosity: the manufacturers usually speak of two capacities for the tapes, and play a bit here with the promises: the native capacity is stipulated, but also the capacity if data compression is used. This is interesting for certain cases, but there are some types of content —such as video— that lend themselves very little to being compressed beyond what the codecs used to encode them already do. It is therefore recommendable to focus essentially on the native capacity of the tapes, and not so much on the capacity data with compression.
There is also a trade-off with the backwards compatibility of these tapes: Normally drives from one generation allow you to write to tapes from that generation and one earlier, and read at least two previous generations: if you buy an LTO-7 drive, you will be able to write to tapes LTO-7 and LTO-6, and read LTO-7, LTO-6 and LTO-5 tapes.
That compatibility standard is not always met, and reading LTO-6 tapes is not supported on LTO-8 drives because these drives rely on barium ferrite technology tapes and LTO-6 supported both barium ferrite and particle technology. magnetic.
What happens to previous generations? Well, they can continue to be interesting, especially because of their prices, which are even lower. Not just on the tapes, but on the drives, which we’ll talk about later.
If we don’t need high write speeds and we can take advantage of the cost per terabyte of these tapes, they can certainly be an option to hold large amounts of data in the long term.
The tapes also have an enviable longevity, and if stored in the right conditions the data can last (theoretically) between 25 and 35 years according to studies. There are other additional advantages, such as the fact that there is a “hard switch” on the tapes that allows them to be write-protected, thus preventing inadvertent scares.
One of the most relevant advances in this technology came with LTO-5 in 2010. It was the first generation to incorporate support for the LTFS file system. This technology allows operating systems to access tape in a similar way to conventional disks or flash drives, making it easy to connect drives to all types of Windows, macOS, or Linux PCs and laptops.
This option is joined by others such as the aforementioned compression —it has its own method, LTO-DC—, WORM technology (write once, protection against accidental or intentional deletions), encryption or, of course, partitioning.
Very cheap tapes, very expensive (and somewhat noisy) drives
It is possible to find an HP LTO-8 Ultrium tape of 12 TB capacity (up to 30 TB with compression, says the manufacturer) for just 90 dollars. A hard drive with that capacity is easily around 300. That is already a first sign of what we can find in a surprising market.
The cost per terabyte is clearly lower when comparing a hard drive with an LTO-8 tape, but it goes even further with previous generation tapes, which are even cheaper. If you need huge amounts of data, that section certainly makes this technology very profitable…in the long run.
Why in the long run? Because while tapes keep the cost per terabyte very low, read/write drives are very expensive. It is easy for an LTO-8 drive not to drop below 3,500 dollars, which makes the initial investment very important. There are several types, but the external ones are recommended because they are easier to use and because the internal ones are somewhat more delicate with the refrigeration section.
It is precisely what a user who had been betting on these storage media, which he used in Linux, pointed out for some time. He himself offered a calculator that allowed us to study the profitability of these investments, and according to his data, LTO tapes pay off when we need more than 150 TB of data.
There is another element that can be annoying for end users: drives are noisy. Not deafening, but clearly audible, something that he himself showed with a small audio and that can also be seen in other independent analyzes.
This user also told how there is some degradation in tapes and drives, which over time can store less data or do it with lower speed.
Even so, interest in this type of storage, which is very popular in companies, is beginning to spread to end users. The community on the r/DataHoarder subreddit is a good example—they talk about a lot of other things, but LTO has a place there—and there’s a getting started guide to LTO technology on another subreddit that’s another good resource for information. You already know: if you need teras and teras of information, maybe this is not a bad option at all.
