A core business area for IBM is providing enterprise solutions using mainframe and server systems. For many years the solutions ranged across many different architectures, most proprietary to the operating system. As part of the solution IBM also developed a range of tape technology, including tape libraries for performing data backups. In 2001 IBM unified much of their server technology, introducing the Z Series of servers using 64 bit architecture, at the same time replacing OS/390 with z/OS as the preferred mainframe operating system. The Z Series server has been designed to also allow Linux to be installed.
IBM have developed many tape drives and tape media designed to serve as a backup solution on their own servers and any other system with the appropriate SCSI interface installed. All these tape drives have been based on the same linear recording principle as the half inch open reel technology, which are often used in movies when a large computer needs to be indicated. These enterprise level tapes are rarely seen for tape data recovery, largely due to the diligence used in ensuring multiple copies of the same data are backed up. We do however see many enquiries requesting tape data conversion, either to make duplicates for distribution, or to change tape or backup format.
3480 and 3590E Data Cartridges
These data cartridges incorporate a single half inch tape spool encased with in a plastic shell with the dimensions 4”x5”x1”. Data is recorded on multiple tracks across the tape simultaneously making a single pass in to the end of the tape, before recording data in the reverse direction, which significantly reduces the number of tape passes required over formats such as the DLT and LTO data cartridges. These tapes are popular for use with robotic tape libraries, which is possible through human and machine readable labels, which later incorporated bar codes, as a more reliable identifier.
When the 3480 was introduced in 1984 it was capable of storing 200MB recording 18 tracks simultaneously. In 1986 hardware based compression was introduced, doubling the capacity to 400MB. For companies creating large amounts of data, such as those undertaking geophysical surveys, an increase in capacity was essential. This need was catered for in 1991 through the development of the 3490E data cartridge, which records 36 tracks simultaneously, allowing 800MB of raw data. Hardware compression was added in 1992 which is quoted as increasing the capacity to 2.4GB.
3590 and 3592 Data Cartridges
These use the same form factor as the 3480 data cartridge, allowing an easy transition, as upgrades to robotic libraries were unnecessary. The first 3590 tape drive (B Model), was introduced in 1995, with two types of media available, “High-Performance” and “Extended High-Performance” data cartridges, the latter allowing double the capacity. The B Model allowed up to 20GB to be stored on the extended data cartridge. The E Model introduced in 1999 double this capacity, with a further increase to 60GB using the H Model developed in 2002. All 3590 tape drives and data cartridges are nicknamed Magstar.
The 3592 range, nicknamed Jaguar, superseded the 3590 when it was released in 2003. The first generation increased the native data capacity to 300GB, a significant increase. Subsequent generations of the drive record a different format to the same data cartridge allowing older cartridges to be reused when the drive has been upgraded. The second generation was named TS1120, with subsequent generations changing the second to last digit for consistency. The 5th generation, the TS1150 was introduced in 2015, which allows 10TB of data to be stored on a single data cartridge, with data transfer speeds of up to 300MB/s.
IBM Tape Data Recovery and Conversion
The reliability of these tape drives and data cartridges, as expected with an enterprise solution, is extremely good. The reliability of these tape data cartridges is enhanced by the need for only a single pass to the end of the tape and back to fill it to capacity. As mentioned earlier, it is rare to see one of these data cartridges arrive for data recovery, as problems when they occur, are usually of little significance due to the enterprise culture of regular and multiple backups.
Although some are seen which have developed a physical problem, usually a media flaw, the majority of this type of tape requiring data recovery are due to operator error. This includes reinitialising and overwriting important data. Recovering data from a type of this type which has been overwritten is usually a relatively simple process, which in the case of relabelling or reinitialising a tape leads to only a small loss of data. It is more common for us to see data cartridges of this type which require tape data conversion.