VXA

VXA is a data backup format for streamers ( tape drives ) originally developed by Ecrix and bought by Tandberg Data after Ecrix merged with Exabyte Corporation to form Exabyte Data . After the takeover by Tandberg Data on November 20, 2006 , the format was not further developed. VXA has new features compared to related processes such as DLT and AIT . VXA is the first tape format to record data in packets.

function

Exabyte and Ecrix refer to the data format as "Packet Technology". VXA uses helical scan recording , in which data packets are recorded in diagonal strips like the images on a video recorder . What is new about the technology is that the packets start with a unique label, the “Packet ID”, and end with an “ECC” checksum . When a strip is written on the tape, it is immediately read again and a comparison is made to determine whether the recording was error-free. A bad packet is repeatedly written to the tape without stopping and rewinding the tape. For this purpose, the data packets including their ID are kept in a buffer memory. Three checksums are stored in the buffer memory to ensure data integrity. There are two heads in the head drum for this purpose . Both heads can be used when reading. Helical scan recording involves a relatively slow tape speed which allows the tape to be stopped more quickly.

Market area

VXA mainly competes with the DDS and DLT-IV formats . According to the manufacturer, the service life of the media is 20,000 "passes", which corresponds to around 1,000 complete backup processes.

Format overview

generation	VXA-1	VXA-2	VXA-3	VXA-4	VXA-5
Publication date	1999	2002	2005	TBA	TBA
Maximum uncompressed amount of data in GB	33	80	160	320	640
Maximum recording speed in MB / s	3	6th	12	24	48
Recording method (modulation / coding)	EFM	PRML
Magnetic track width			5.7 µm
head		Ferrites	TFMR

VXA-3

Exabyte launched two lines of VXA-3 technology: VXA-320 in 2005 and VXA-172 in 2006. VXA-172 drives are limited to 86 GB per tape, but can be activated for a fee. Otherwise they are identical. VXA-3 was the first helical track recording system with "MR" heads ready for the market. These are thin film magnetic heads (TFMR) that use the GMR effect .

The storage sizes are physically specified uncompressed. Exabyte assumed a possible compression to 50% and advertised the products with it.