Magnetband (LTO)

Tape drives are seen by many as yesterday's technology. In fact, data centers and companies still back up large amounts of data on magnetic tape today, mostly in the LTO format. When a tape archive is dissolved, it often holds years of company data. This entry explains what a magnetic tape is and what applies to decommissioning.

What is a magnetic tape?

With magnetic tape, the data lies in tracks on a thin tape wound up in a cartridge. A drive winds the tape past the read/write head. Unlike a hard drive, there is no fast direct access: to read specific data, the tape has to be wound to the right position. In return, tapes are inexpensive per terabyte, long-lasting and can be stored offline, that is, separated from the network. This makes them a protection against ransomware.

LTO generations

LTO is further developed by a manufacturer consortium. Each generation increases the capacity. Which older generations a drive can still read is regulated differently for each generation. For a tape archive, you therefore need a suitable drive.

Generation	Native capacity per cartridge
LTO-7	6 TB
LTO-8	12 TB
LTO-9	18 TB
LTO-10	30 TB, 40 TB as a variant with new tape material

Manufacturers also state a compressed capacity, which is considerably higher depending on the data. There are also WORM cartridges (Write Once, Read Many), which can only be written to once, for example for audit-proof archives.

What to note when retiring devices

• Record contents: Tapes carry a barcode label with a volume identifier. Keep the identifier and content in a list.
• Erasing: A tape can be overwritten in the drive. With large capacities, this takes a long time and requires a suitable drive. With WORM cartridges, overwriting is not possible.
• Degaussing: A sufficiently strong degausser makes the data unreadable. Modern LTO tapes have a high coercivity, that is, strong magnetization. Not every device is sufficient for this. In addition, the factory servo tracks are destroyed, and the tape is unusable afterwards. More in the entry Degaussing.
• Destroying: According to DIN 66399, magnetic tapes belong to the Material class T. The security level depends on the protection requirement of the data.

Tapes often occur together with servers and storage systems. How a data center teardown works is described in our guide sell used servers.

Magnetic tapes and Second IT

Second IT processes data carriers from the entire data center. At goods receipt, every medium is recorded and registered. Functional drives and hard drives are erased with Blancco, with a digitally signed certificate per device. Data carriers that cannot be erased in an audit-proof manner are securely destroyed in-house and documented. Clarify the type and quantity of your tapes in advance in the quote. More about certified data deletion.

Frequently asked questions about magnetic tape

What is LTO still used for today?

Mainly for backups, long-term archives and copies that are stored separately from the network. Tapes are inexpensive per terabyte, long-lasting and need no power on the shelf.

Can an LTO tape be erased and reused?

Yes, rewritable tapes can be overwritten in the drive and then reused. After degaussing, by contrast, an LTO tape is generally unusable because the servo tracks are destroyed.

Which DIN 66399 class applies to tapes?

Magnetic tapes belong to material class T for magnetic data carriers. For this, the standard defines security levels T-1 to T-7 with increasingly smaller particle size.

What does WORM mean for LTO tapes?

WORM stands for Write Once, Read Many. Such cartridges can only be written to once, for example for audit-proof archives. Overwriting is not possible with WORM cartridges. When decommissioned, only degaussing or destruction remain.

Why do LTO tapes protect against ransomware?

Tapes can be stored offline, that is, separated from the network. Malware cannot reach a cartridge on the shelf. This makes tapes a protection against ransomware. To access a tape archive, however, you need a suitable drive.