Z-TapeBackup

Tape Backup Software for tape drives
LTO (UltriumTM), DAT, DDS, DLT and more

Tapes are the ideal backup medium for companies that have to store lots of data for a long time. They are known for the following properties:

High data capacity
Excellent cost per gigabyte ratio
Higher backup write speeds that traditional hard drives
Very long durability

Tape Drives

Tape drives are used to read data from tape or write data to tape. A normal tape drive has one drive slot and can’t store any tapes. Tapes have to be loaded and unloaded manually.

Autoloader

Autoloader have one drive slot and additionally multiple storage slots. Tapes can be loaded automatically from their storage slot to the tape drive.

Tape Library

Type Libraries not only store multiple tapes but also have multiple tape drives. They usually only come into play when extreme data storage capacity and access is needed.

Current tape drives come with extra features like hardware compression or encryption. When investing into a tape backup setup the tape drive will be by far the most expensive item, while tapes and even the software cost considerably less.

Data stored on tapes is accessed sequentially which makes search queries for specific files more time consuming. Z-TapeBackup can store the tape position of files, makeing restores of single files considerably faster.

Tape Technology

Magnetic tape is used to store data since the 1950s and can look back on a long development and usage history. Through the years new technologies and storage formats have been developed. The most widespread used technology today is LTO.

LTO

LTO (Linear Tape-Open) is the most commonly used tape data storage technology today. It was developed and introduced in the 90s by IBM, HP and Seagate. Today the active development of the standard is lead by IBM, HP and Quantum. LTO is an open standard which allows other companies to acquire licences and manufacture their own LTO tapes and tape drives. One of the biggest tape drive manufactures today is Overland-Tandberg (prev. Tandberg Data).

Generations

Every couple of years a new LTO generation is introduced. With each generation the data capacity usually doubles and some generations include new features.

Generation 3 introduced WORM tapes (Write Once Read Many) which can’t be overwritten
Generation 4 introduced hardware AES-256 encryption
Generation 5 introduced partitioning into two areas
Generation 6 extended the partitioning to four areas

A tape drive of a particular generation supports tapes of the same generation and also usually tapes of one or two generations below. But tapes of a higher generation are not supported.

Capacity

LTO tape drives support hardware compression. For every LTO tape a native capacity and a compressed capacity is specified. Tapes of generation 8 (from 2017) have a native capacity of 12 TB and a compressed capacity of 30 TB. For the compression a compression factor of 2.5:1 is presumed. Many file formats nowadays already include data compression by default, like docx, jpg, mp3 or mp4. This is why the advertised compression factor of 2.5:1 can rarely be achieved in practice. You therefore shouldn’t rely on being able to store the amount of data equivalent to the compressed capacity on tape. Always take into account how well your data can be compressed. It usually comes down to testing if the desired data fits on a tape when compression is enabled. If in doubt only write the amount of data equivalent to the native capacity to tape.

Other Technologies

DAT

DAT (Digital Audio Tape) drives are based on the 3.5” format (4mm technology). Conventional DAT drives are available in sizes of 2 to 160 GB. DAT tape drives record data using the helical track procedure (helical scan). Tapes are very cheap, although comparatively not as durable as other drive types. The storage period is restricted, the requirements for the storage of such a medium are very high.

Most capacity figures for DAT are determined with unrealistically high compression rates. In practice, only the uncompressed value is of any relevance. Because of the relatively large “cut” due to bad tape sectors (“Drops”), the real achieved capacity is usually smaller. In addition to that, DAT drives using the DDS-3-standard recognise and report pollution to the head too late. However, these devices are very popular and used frequently.

DLT

The DLT (Digital Linear Tape) technique was developed in 1994 by DEC. It also uses longitudinal tracks, but only one reel. The tape is wound onto a fixed reel in the drive with a special mounting mechanism.

The drives offer a transfer rate of 10 MB/sec and data capacities between 40 and 800 GB with automatic error checking (parity checking, CRC and EDC (Error Detection Code) of the data blocks).

QIC SLR

SLR (Scalable Linear Recording) is a recording method for tape drives and the product name of Tandberg drives. The tape drives of the Tandberg SLR series (Single Linear Recording) are suitable for 4 to 200 GB of data at a transfer rate of up to 600 MB/min. The SLR technology was already developed in the end of the 70s, and the devices were initially known as QIC tape drives. Because of their robust mechanical layout, SLR drives offer a maximum of data security and reliability. Because 80% of the wear parts are contained in the data cartridge, including the tape guide, the wear and tear is extremely low. The modern drives of Tandberg Data are all equipped with Multi-Linear-Recording (MLR) technology, by which both the capacity of a cartridge and the speed is increased. Through magnetic head servo technology, unique in this class, a very high technical reliability of the drives is achieved. According to experience, Tandberg equipment runs very cleanly and stable. It is used in the professional sector.

QIC Travan

Travan drives (Quantum, Seagate, Certance) are the ideal backup solution for smaller servers, workstations, PCs and notebooks. They are particularly suitable for businesses with a few PCs or home offices, where only small amounts of data have to be backed up. Travan drives are characterized by their simplicity. They consist almost exclusively of the drive motor, the read/write head and some electronics. That makes them very robust and extremely reliable. Problems that one knows from e.g. DAT drives are not an issue here. Quantum Travan drives are now available in the 7th generation with 20 GB net capacity.

Z-TapeBackup supports all common tape drives including: LTO (Ultrium), DAT, DLT, DDS, TRAVAN, VXA, QIC, MLR, SLR and AIT