Data Recovery

Tape Technology

Tape backup technology is critical to today's dynamic businesses. Regular backup ensures the ability to protect and preserve data. Dell's PowerVault storage products include a full line of tape backup devices: single tape units, autoloaders, and tape libraries. Tape drives operate by magnetically storing data on removable tape cartridges. There are two main types of tape units, helical scan and linear.

Helical Scan Technology

This image is a representation of a helical scan tape

Helical scan technology uses digital analog tape (DAT) and can be either 4mm or 8mm wide.

In physical appearance, helical scan drives are similar to a standard VCR.

The tape is wrapped around the head, which is inclined or slanted slightly from the vertical.

Linear Technology

This image is a representation of a linear scan tape

Linear technology uses half-inch wide single-reel tapes.

The tape is loaded at the beginning of the tape cassette and passed in a linear fashion across the surface of the tape head without being wrapped around the head.

The tape passes multiple times in both directions at a relatively high speed.

Capacity and Compression

Capacity is a measure of how much data can be stored on a single tape. Compression is a way to store data in a format that requires less space. Dell tape drives can use compression to store more data on a tape. Compression is generally expressed as a ratio. For example, a customer has a tape cartridge that has a capacity of 20GB. A 2:1 compression ratio will allow 40GB to be stored on the tape. However, not all files are compressible so this capacity may not be seen.