The MO the merrier

'|'SPECIAL TO GCNFor large-scale data archiving and retrieval, optical jukeboxes, also known as optical disk libraries, bring a fast return on investment.Technically, optical jukeboxes are systems with drives that handle multifunctional magneto-optical disks as well as CD-ROM, CD-R, CD-RW and DVD-RAM or DVD-ROM media. There are trade-offs among them in price and performance, but MO jukeboxes excel in the highest levels of reliability, storage capacity and overall performance.The MO jukeboxes listed in this guide are equipped with robotic arms and up to 12 drives. All use 5.25-inch disk cartridges capable of holding up to 9.1G of data.The cartridges are stored in shelves or magazines within the unit for automatic retrieval. With the aid of software, fast SCSI-2 interfaces and networking capability, an MO jukebox with several hundred disks can handle terabytes of information.The drives used in MO jukeboxes work with both rewritable and write-once-read-many (WORM) media, an advantage over competing optical storage technologies. Data can be rewritten to a rewritable MO disk more than 100 million times and, because it uses laser technology, it's fairly difficult to inadvertently wipe data from the disk.width="250">As the name suggests, WORM technology allows data to be written only once but read limitless times. This security feature satisfies most government and regulatory requirements for the safety of data.The benefits of MO jukeboxes can be put into eight categories. Once you've invested in an MO jukebox, the cost of adding more gigabytes of storage is limited to the price of the MO media. And as you increase capacity, the cost of storage can go down to a few pennies per megabyte of data. The robotics in MO jukeboxes are highly dependable, with mean swaps between failure (MSBF) rates of 2 million or more in many cases.If you want faster swap times with some fail-safe protection against a drive failure, select a system with multiple drives. If one drive goes down, others instantly take up the load without missing or losing data. MO disks are inherently more stable than hard disks, magnetic tape and even CD-ROM or DVD media. MO disks are made of polycarbonate plastic, the same material used in manufacturing bulletproof glass. Because the data is sandwiched between two sheets of polycarbonate, it isn't subject to dust, sunlight or other forms of contamination.The disks also avoid head crashes because the laser array used to record and read data never comes in contact with the media itself. Because a laser beam is used to change the polarity on the media to create data, existing data can't easily be erased or altered magnetically.Under normal conditions, data stored on an MO disk has a likely shelf life of 30 to 50 years; new disk technologies will soon bring the minimum data shelf life to 100 years or more. MO jukeboxes can store gobs of data; their 5.25-inch, 9.1G disks that can store approximately 12.3 million pages of information are fast becoming the new standard. Plasmon PLC's G638, which uses 9.1-G cartridges exclusively, has up to 638 slots. This tallies up to a storage capacity of a whopping 5.8T.MO experts from Hewlett-Packard Co. predict that next-generation MO disks will have up to 40G of storage capacity, to be followed eventually by 120G disks. MO drives are random-access, making them faster than tape drives, which must seek out specific data serially. HP says its Surestore Series, with 9.1G drives, has true fast-synchronous burst data transfer rates of up to 10 Mbps and sustained transfer rates of up to 6.1 Mbps. Statistics published by other manufacturers, including Plasmon, show similar performance capabilities. You can write to an MO disc over 100 million times, using it just as if it were a hard drive, or use WORM disks to write once.By contrast, you can't write to a CD-ROM disk at all. You can write to CD-R and CD-RW disks, but you need special software and premastering procedures for batch writing. And even though DVD technology is on the rise, it comes in a variety of formats, lacks comprehensive standards and doesn't offer the media security that MO does.Virtually all MO jukeboxes can read MO disks from any manufacturer, provided they are standards-compliant. A system loaded with 5.2G disks can also read 2.6G disks as well as the earliest MO disks formatted for 650M of data. Most MO jukeboxes are in product families and usually defined by their overall capacities, which makes it easy to scale your capacity. For example, HP's Surestore 220mx, with 220G of storage, works easily with the company's high-end products, up to the 2200mx, with 2.2T of storage. The company also has conversion kits for upgrading any of its 2.6G or 5.2G jukeboxes to 9.1G systems. MO technology adheres to standards established by the International Standards Organization, which guarantees interoperability among products. For buyers, this amounts to a safeguard against premature obsolescence and eliminates dependence on a single supplier.XXXSPLITXXX-