Removable disk storage array emulating tape library having backup and archive capability

Abstract

A hard disk drive based data archive system emulating a tape archive system includes a hot pluggable multi-drive magazine having a housing for holding a plurality of hard disk drives, each drive connected to receive power and data from the magazine in a controlled fashion, and at least one magazine receiving system for physically receiving the magazine and for thereupon providing power, data and control connections to the magazine, such that when the magazine is received within the magazine receiving system, the hard disk drives selectively receive power and data connections via the magazine and receiving system from a host computer. The magazine may be hot-disconnected from an active computing system environment and removed to an archive rack wherein each disk drive is periodically checked to ensure functionality and to provide some limited-bandwidth data retrieval functions via a network connection to the archive rack. A file mark structure enables a disk drive in the magazine to emulate functionality of a tape cartridge.

Description

FIELD OF THE INVENTION [0001] The present invention relates to methods and apparatus for protecting user data within a computer system. More specifically, the present invention relates to a removable rotating disk drive data storage array for emulating tape library functions including backing up and archiving user data. BACKGROUND OF THE INVENTION [0002] The need for effective and reliable backup and archive of user data information is well known. Considerable information system (IS) resources are devoted to providing backup and archive of information resident in computers and servers within any organization that produces and / or relies upon digital information. [0003] The term “backup” means that periodically, such as each day, a backup record is made which mirrors then-present information content of computer active memory embodied as semiconductor random access memory, and / or a hard disk drive or drives, of a computer or computer server. This backup operation usually, although not ...

AI Technical Summary

Benefits of technology

[0020] A more specific object of the present invention is to realize vastly improved tape storage backup and archive system functionality with performance, reliability and cost advantages of hard disk drive technology in a network-attached storage system.

[0021] Yet another specific object of the present invention is to provide a data storage backup and archive library which does not require operator intervention or robots in order to move a tape cartridge between a storage bin and a tape transport with a cartridge handler mechanism, thus overcoming limitations and drawbacks of prior tape cartridge handling solutions associated with cartridge loaders and tape libraries. In fact, one object of the present invention is to eliminate the cartridge media transport mechanism entirely.

[0024] One more specific object of the present invention is to provide a magazine of hard disk drives which may be installed and used in a high speed, high bandwidth data storage rack electrically coupled to a high performance computer, and which may be removed to, installed in and electrically accessed at a data archive rack monitored by a supervisory controller and connected to the high performance computer via a lower bandwidth network connection.

Problems solved by technology

One drawback of archival tape cartridges is that once they are removed to the secure storage site, they become presently unavailable to the computing system; and, depending upon conditions such as temperature, humidity, handling and storage conditions within the storage site, the tape / cartridge may deteriorate or degrade.

If later needed, the archived user digital data information on the tape media of such cartridges may turn out to be unavailable.

Such procedures tend to be time consuming, labor-intensive, and evidently expensive.

Repeated handling and use of a tape cartridge shortens its useful life and can directly lead to its failure as a data archive resource.

One further drawback of tape archiving methods and technology is that drive transports are being constantly improved and upgraded technologically.

It has proven very difficult to provide backwards-compatibility in tape archive systems such that more recent tape drives are able to read and recover user data from older tapes using less dense data recording formats, all other considerations being the same.

One other drawback of tape archiving methods has arisen during efforts to re-use archive tapes because of less than complete erasure of overwritten data.

This problem has led some users to treat tape cartridges as one-use devices, greatly adding to the expense of tape archive systems operations and management.

Also, because the tape cartridge is not a sealed system, external contaminants and influences may prevent a tape transport mechanism from successfully reading an archive tape.

Further, tape cartridge handling equipment including tape transports, tend to be very complicated electro-mechanical structures, with multiple tape path control loops and other interactive tape handling processes.

If any one of these processes fails or degrades, the tape may be damaged or destroyed.

Moreover, tapes written on one tape transport may not be readable on another tape transport because of accumulation of head-tape alignment errors.

These prior disclosures fail to provide any teaching or suggestion that the disk drives or disk drive arrays performing the virtual tape drive emulation can be physically removed from an active data store and relocated to a secure data archive location and then provide the archive function typically performed by removable archive tape media.

Rotating hard disk drives are known to be susceptible to, and can be damaged by, sharp shock forces incident to handling.

Such forces may cause the hard ceramic head sliders to deform the relatively soft aluminum alloy disk substrate.

Accordingly, while tape storage has been emulated by disk storage, rotating hard disk drives are generally more fragile than tape cartridges from a media handling perspective.

Therefore, a hitherto unsolved need has remained for a removable hard disk storage array capable of emulating tape library backup and archive functions in a manner overcoming limitations and drawbacks of the prior art.

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