The MO the merrier

The MO the merrier<@VM>MO devices do a number on storage and retrieval problems

• Jun 28, 2001

Magneto-optical jukeboxes are music to the ears of managers who need capacity, scalability and reliability

BY J.B. MILES'|'SPECIAL TO GCN

For 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.

Terabytes 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.


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color="#000000">The Lowdown

' What is it? A magneto-optical jukebox is a robotic device with one or more disk drives and several shelves or magazines for storing up to hundreds of rewritable or WORM optical disks.

' How does it work? It uses dedicated software to automate loading and unloading optical media to the drives, so that stored data can be transferred at high speeds among computers and network servers. Third-party vendors also make jukebox management software.

' What about platform and OS support? Most MO jukeboxes support virtually all platforms and operating systems. But check to see if the one you're interested in supports the systems you use.

' What is online drive replacement? Several manufacturers offer online drive replacement options, with which you can replace a failed drive on the fly without interrupting the jukebox or server.

' Must-know info? MO jukeboxes offer unlimited capacity, fast data transfer times and high levels of data security when WORM disks are used. Document imaging, electronic publishing, computer graphics, computer-aided design, secure archiving, digital video, medical imaging and multimedia are a few of the applications they support.
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.

Price and performance. 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.

Reliability. 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.

Stability. 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.

Large capacities. 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.

Plasmon PLC's G638 has 638 disk slots and 5.8T of capacity with data transfer rates between 3.1 and 6.1 megabytes/sec. Its price starts at $108,512.

High speeds. 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.

Flexibility. 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.

Scalability. 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.

Standards. 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.

J.B. Miles of Pahoa, Hawaii, writes about communications and computers. E-mail him at [email protected].

Company	Product	Capacity in gigabytes	Disk slots	Drives	Average disk exchange time in seconds	Data transfer in megabytes per second	Mean swaps between failure	Price
Disc Inc. Milpitas, Calif. 408-934-7000 www.disc-storage.com	Orion D150U	1,274 to 1,547	140 to 170	2 to 8	3.7	2.5 to 5	2 million	$50,000
	Orion D245	1,866 to 2,321	207 to 257	2 to 12	3.7	2.5 to 5	2 million	$58,000
	Orion D280U	2,184 to 2,639	260 to 290	2 to 12	3.7	2.5 to 5	2 million	$69,000
	Orion D525	4,141 to 4,778	457 to 527	2 to 16	3.7	2.5 to 5	2 million	$93,000
	Orion D525U	4,141 to 4,778	457 to 527	2 to 16	3.7	2.5 to 5	2 million	$106,000
	Orion D1050	8,299 to 9,573	914 to 1,054	4 to 32	3.7	2.5 to 5	2 million	$163,000
Hewlett-Packard Co. Palo Alto, Calif. 650-857-1501 www.hp.com	Surestore 2200mx	2,166	238	4, 6 or 10	6.5	3.1 to 6.1	2 million	$69,969
	Surestore 1200mx	1,165	128	4 or 6	6.5	3.1 to 6.1	2 million	$34,649
	Surestore 700mx	692	76	2	6.5	3.1 to 6.1	2 million	$15,499
	Surestore 600MX	582	64	4	6.5	3.1 to 6.1	2 million	$20,249
	Surestore 300MX	292	32	2	6.5	3.1 to 6.1	2 million	$12,977
	Surestore 220MX	218	24	1 or 2	12	3.1 to 6.1	1 million	$5,393
IBM Corp. Armonk, N.Y. 800-426-2255 www.ibm.com/storage	Enhanced 3995 C60	104	20	1 or 2	2.8	3 to 5.5	1 million	$8,995
	Enhanced 3995 C62	270	52	2	2.6	3 to 5.5	2 million	$22,500
	Enhanced 3995 C64	540	104	2 or 4	2.8	3 to 5.5	2 million	$31,300
	Enhanced 3995 C66	811	156	4 or 6	2.8	3 to 5.5	2 million	$49,000
	Enhanced 3995 C68	1,341	258	4 or 6	3.1	3 to 5.5	2 million	$68,500
Maxoptix Corp. Fremont, Calif. 800-848-3092 www.maxoptix.com	MX620	82 to 104	20	1 or 2	6	2	1 million	$6,995 up
	MX640	164 to 208	40	1 or 2	6	2	1 million	$1,0650 up
	MX6126	516 to 655	126	2 to 6	10	2.5	2 million	$34,682 up
	MX 6202	828 to 1,050	202	2 to 6	10	2.5	2 million	$40, 580 up
	MX 6278	1,140 to 1,450	278	2 to 6	10	2.5	2 million	$51,850
Micro Design International Inc. Lake Mary, Fla. 800-228-0891 www.mdi.com	SEL-010104	104	20	1	6	3.5 to 4	.8 million	$10,299
	SEL-020104	104	20	2	6	3.5 to 4	.8 million	$13,799
	SEL-020166	166	32	2	6	3.5 to 4	.8 million	$17,999
	SEL-020270	270	52	2	9	3.5 to 4	1.5 million	$25,899
	SEL-040540	540	104	4	9	3.5 to 4	1.5 million	$41,199
	SEL-040811	811	156	4	10	3.5 to 4	1.5 million	$51,199
	SEL-061341	1,341	258	6	10	3.5 to 4	1.5 million	$89,999
	SEL-062600	2,600	500	6	13	3.5 to 4	1.5 million	$137,999
Plasmon PLC Eden Prairie, Minn. 952-946-4100 www.plasmon.com	G164	1,500	164	4 or 6	6.1	3.1 to 6.1	3.8 million	$50,730 up
	G238	2,200	238	4, 6 or 10	6.2	3.1 to 6.1	3.8 million	$64,370 up
	G638	5,800	638	6, 10 or 12	6.4	3.1 to 6.1	3.8 million	$108,512 up
	M20	104 to 184	20	1 or 2	2.7	3.1 to 6.1	1.5 million	$7,395
	M32	166 to 291	32	1 or 2	3	3.1 to 6.1	1.5 million	$10,795 up
	M52	270 to 473	52	2	6.1	3.1 to 6.1	2.8 million	$20,350
	M104	540 to 946	104	2 or 4	6.3	3.1 to 6.1	2.8 million	$24,400 up
	M156	811 to 1,400	156	2, 4 or 6	6.7	3.1 to 6.1	2.8 million	$32,400 up
	M258	1,300 to 2,300	258	2, 4 or 6	7.2	3.1 to 6.1	2.8 million	$55,392 up
	M500	2,600 to 4,600	500	2, 4 or 6	8.1	3.1 to 6.1	2.8 million	$94,336 up
Sony Electronics Inc. San Jose, Calif. 408-432-1600 www.ita.sel.sony.com	OSL-2001	46 to 52	20	1 or 2	5	4 to 5	1 million	$5,596 to $7,996
Western Scientific Inc. San Diego, Calif. 800-443-6699 www.wsm.com	WJBP40FN-C5	40	16	2	12	5	n/a	$13,618
	WJBP80FN-C5	83	32	2	10	5 5	n/a	$20,908
	WJBP160FN-C5	166	64	4	10	5	n/a	$34,938
	WJBP330FN-C5	333	128	4	10	5	n/a	$47,292
	WJBP600FN-C5	619	238	6	10	5	n/a	$80,712