RAID is hot. In the past two years, the cost per meg dropped from more than $2 to less than 70 cents -- in some cases, to as low as 45 cents a meg. RAID arrays are getting much faster. They store more data.
RAID has come a long way since 1987, when engineers at UC Berkeley developed it to reduce the cost of mass storage and improve reliability. The idea was to combine several small, inexpensive disks that would replace large, expensive ones. The engineers also wanted to protect against disk failure by including redundant information -- hence the name RAID (Redundant Array of Independent Disks). Industry took up the challenge but changed it to "Inexpensive" -- a misnomer at the time.
Initially, RAID was marketed to large corporations and mainframe users who needed to protect their data and make it more available. While many small companies could also have benefited, few of them could afford to cough up tens -- or in many cases, hundreds -- of thousands of dollars for a system.
Like all computer products, RAID has gotten much cheaper. New markets are emerging. RAID makers now target low- and mid-range markets with cost-effective products.
"The mid-range market is growing," says Gary Holtwick, Hitachi Data Systems' (Santa Clara, CA 408-970-1000) VP of marketing. "You can sell anything from consolidated servers to large systems, which is quite a span. Open systems is definitely in vogue. Very flexible."
One growing area for RAID is retail. Large stores track thousands of small files (transactions). Many users access these files from their workstations.
"RAID 5 shines best in this type of application. It provides independent access to all the drives in the array, so multiple files can be accessed and processed at the same time," says Hal Mercer, marketing manager at CyberStorage Systems (Littleton, MA 508-486-0005).
"In prepress workflow, with its large graphics and image files, RAID 3 is the natural choice because all drives are accessed at once," says Mercer. "This provides large bandwidth for the efficient transfer of large sequential files. RAID 0 is excellent when you need to capture digital information and pass it rapidly to another location. Extremely critical data that must be protected and available at all times can benefit from RAID 1."
One new innovation in RAID is Level 7, developed and patented by Storage Computer Corporation (Nashua, NH 603-880-3005). It stores several terabytes and executes reads and writes faster than RAID levels 3 and 5. It provides the same, if not higher, levels of protection. VARs like Advanced Computer & Network Corporation (Pittsburgh, PA 412-683-9010) resell Storage Computer's RAID 7 products for interactive television and video-on-demand applications.
As RAID technology gets better, it's reaching into new markets such as video servers. Fibre channel increases data transfer to 200 Mbyte/s. Many vendors are now releasing their fibre channel-based products.
Fibre channel also links with the relatively new Ultra SCSI technology. Ultra SCSI, or double SCSI-2, is a serial interface that transfers data using the fast-wide bandwidth at up to 40 Mbyte/s. You can use it for real-time video applications.
But Ultra SCSI isn't the be all and end all. IBM's Storage Systems Division (San Jose, CA 408-256-1600) claims that their scalable subsystem design, SSA (Serial Storage Architecture), is the open storage interface for network-centric computing.
SSA lets multiple devices, subsystems and local host processors communicate at the same time.
A single configuration can include up to 128 devices. SSA transfers data as fast as 80 Mbyte/s. But SSA has yet to gain the widespread acceptance that SCSI enjoys.
Another major improvement -- Dynamic Growth and Reconfiguration (DGR) -- lets system administrators quickly and easily add capacity and change RAID levels while the system is online. The result is greatly reduced administration costs, simpler upgrades and optimal RAID-level tuning.
"DGR is very hot now," says Ted Chen, VP at Storage Dimensions (Milpitas, CA 408-894-1331). "You can add a disk drive to increase capacity and change RAID levels while it's online. Before, you had to backup your data, shut down the system, add the drive, reconfigure the RAID and restripe it back onto the disk.
"This took up to 10 hours. When it happened, administrators always worried about getting the system back online in time.
"With DGR, the controller does the auto restriping. In addition to adding drives, you can also change the RAID level. Add another disk for RAID 5 on the fly and then change the level to 3 for long sequential files. It's great for the imaging market, which consumes a lot of data. Imaging also has the highest rate of capacity growth."
In addition, there's also the ever-present need for more storage. No matter how much storage you have, you'll need more in the future.
Last year, the potential capacity doubled, with many vendors releasing 9 GB drives. This year, capacity will at least double, to 18 gigs.
There's even talk of 23 GB drives in a RAID system. This will reduce the cost per meg even further.
"The 9 GB drives lowered the cost substantially," says Chen. "It will drop to less than 45 cents a meg. At the moment, some interesting trends are emerging that are particularly important to document imaging.
"As hard disk storage gets cheaper, there's more encroachment on optical storage. Hard disk storage costs less than ever before. It could soon reach a stage where it's more cost-justified to use hard disk storage than optical.
"CD-ROM libraries need to be serviced. As access increases, they'll have a higher failure rate than RAID. Right now, capacity seems to be doubling every year or so -- and prices per meg are dropping by 35%.
"RAID will be able to satisfy the needs of the imaging and multimedia markets," says Chen.
CyberStorage Systems recently delivered more than 100 RAID arrays for the Korean educational system. The units ranged in capacity from 6 GB to 24 GB.
They were integrated into video-on-demand systems that deliver multimedia content to the desktops of Korean students. The cost was less than anyone ever imagined -- even a few months ago.
"The 18 gigabyte hard drives will be coming soon," says Paul Marcussi, product manager at CLARiiON (Southboro, MA 508-480-7350). "It took us two years to move from 4 GB drives to 9 GB drives, but we're already working on 18 gigabyte drives.
This will reduce the cost per meg by half, to around 30 or 33 cents. Consumers will get a lot more storage for their dollar.
"This is just part of the trend to make RAID less complicated. We're making it easier to install and manage, so you don't have to be an expert to install a system. We're also moving into new areas.
"We're working on a new RAID 3 product as well as developing products for the telephony and central office market. Our new fibre channel products will be released soon.
"The next few months will see a host of major new products released by many different vendors. IBM may bring out a PCI bus system for the high-end market in the spring. This would mean a common platform. PCI adapters should also become fairly standard. A few months ago, PCI was very immature.
It's now greatly improved. Several PCI adapters are now being tested for different products. The fibre channel will also mature in the next 12 to 18 months as more people move towards this technology."
RAID arrays help meet the demand for cost-efficient network storage and rapid access to data. Here are some of the companies breaking new barriers in RAID cost-efficiency:
Adaptive Information Systems (Mission Viejo, CA 714-587-9077) offers the AdaptStor ($15,000+) family of storage management systems. Major product components include the 6970 Series optical jukebox subsystem, 6500 Series RAID subsystem and automated HSM software.
The system is designed for high-volume, data-intensive enterprise apps such as image processing, medical imaging, data warehousing, document and database management and CAD/CAM.
The AdaptStor 6500 RAID subsystem features large-capacity 3.5" disk drives and nonvolatile cache memory up to 256 MB. Store 4.6-66.6 GB. Scale to 2.3 TB. Each model supports RAID Levels 0,1 and 5 and can mix different levels.
Advanced Computer & Network's (Pittsburgh, PA 412-683-9010) RAID Level 7 lets all devices operate asynchronously. Data is sector-striped across the array. A dedicated parity drive is updated with asynchronous transfers to and from the central cache.
Features: Process-oriented real-time operating system on an embedded array-control microprocessor. Up to 12 host interfaces and 48 drives linear capacity. Standard SCSI drives, PC buses, motherboards and memory. High-speed internal-cache data transfer bus (X-BUS). Multiple drive devices that can be hot standbys.
Andataco's (San Diego, CA 619-453-9191) new generation of RAID arrays, called GigaRAID, combines the fault tolerance of RAID with their Enterprise Storage Packaging (ESP) technology. GigaRAID has single active or dual active/passive controllers, each employing an I960 Intel RISC microprocessor. Visual, audible, e-mail and Web-based alarms alert you before a system's disk drives, fans or power supply fails.
GigaRAID is scalable from desktop to data center. It supports up to 14 drives, with RAID 0, 1, 0+1, 3 and 5, for up to 127.4 GB of online storage capacity. The ESP transfers data at Ultra SCSI (40 Mbyte/s) rates and supports 10,000 RPM drives. Add the client/server RAID Management Utility for remote monitoring and control across the network.
ATTO Technology's (Amherst, NY 716-691-1999) new ExpressRAID software speeds system throughput and response time for data-intensive environments. The package comes with a disk utility that offers disk formatting, partitioning, optimizing, benchmarking and Level 0 support.
Level 0 offers simultaneous data reading and writing across several drives and speeds data transfer to and from the drives. This reduces access time by overlapping the drive seeks, resulting in overall faster response time. ExpressRAID's auto-detection feature simplifies setup and configuration by letting the user create a volume and mount the drives in one easy step. ExpressRAID supports RAID Level 0 across multiple host adapters.
BoxHill Systems' (New York, NY 212-989-4455) Fibre Box is a hot-swappable, dual fibre channel arbitrated loop storage system with data transfer rates up to 200 Mbytes/s and capacities of up to 72 GB per enclosure (1,125 GB per loop).
BoxHill has also released RAID Box 5300 Turbo, a disk array subsystem with an aggregate throughput of 60 Mbyte/s. Protect 2-504 GB of data.
Ciprico's (Minneapolis, MN 612-551-4000) 6500 Series of high-performing entry-level disk arrays is one of the first RAID 3 disk arrays based on ATA-2 drive technology. The $17,000+ 6500 connects to hosts with an Ultra SCSI interface and supports burst transfer rates of 40 Mbyte/s. The ATA-2 drive capacity starts at 17 MB per array.
CLARiiON (Southboro, MA 508-480-7280) has extended their family of disk arrays with the CLARiiON Series 3000. The Series 3000 is the first CLARiiON disk array with a future upgrade path to a fibre channel host interface. The Series 3000 shrinks costs and grows capacity per square foot -- it provides up to 30 3.5" drives per enclosure and up to 90 drives in a rackmount cabinet.
Features: Completely redundant subsystem architecture to protect against component failures. Online maintenance for fast "hot-plugging" of system components. Advanced system design with mirrored write cache to increase performance and maintain data integrity.
Conley's (New York, NY 212-682-0162) new SR-50 RAID subsystem sports a fibre channel connection that multiple host computers can share. All single points of failure are eliminated with redundant features like mirrored cache, dual-active controllers and auto-failover of host data paths. All active components are hot swappable.
Multiple Ultra SCSI drive channels let the SR-50 transfer data to the hosts as fast as the host data path can carry it. Hosts connect via 40 Mbyte/s Ultra SCSI or optional 100 Mbyte/s fibre channel interfaces.
Digital (Maynard, MA 508-493-5111) assaults enterprise storage with the StorageWorks RAID Array 450. Features: Hot-swappable disks, power and cooling. Concurrent support for RAID levels 0, 1, 0+1 and Digital's level 3/5.
Command Console GUI-based software makes it easy to configure and monitor StorageWorks RAID Array 450 and Enterprise Storage Array units anywhere on the network from a TCP/IP host system. It supports multiple platforms and features built-in security and protection.
DLI/Dilog (Irvine, CA 714-476-7171) boasts the latest advancement in RAID technology with the Ultra-Windjammer RAID controller. Highlights: 40 Mbyte/s 16-bit Ultra SCSI interface. Concurrent RAID levels 0 and 1. Hot swappability. Support for up to 30 SCSI disk drives.
Hitachi Data Systems (Santa Clara, CA 408-970-1000) has licensed Emulex Corporation's (Costa Mesa, CA 714-662-5600) fibre channel chipset for use in HDS' 5700 Midrange Disk Series, which runs in Unix, Windows NT, NetWare or AS/400 settings. Fibre channel boosts performance five-fold over previous I/O technologies.
The 5700 series has mainframe-class processing and data security to client/server environments. The subsystem protects data with either disk mirroring or RAID 5 support. The 5700 series is Microsoft-certified for Windows NT.
IBM (San Jose, CA 408-256-1600) announced a high-speed, high-capacity storage system for servers running OS/2, NetWare and Windows NT. The new 3527 SSA Entry Storage subsystem gives PC users the same Serial Storage Architecture (SSA) benefits enjoyed by supercomputers and midrange servers. Using IBM's 4.5 GB and 2.2 GB SSA "hot swap" disk drives, it runs up to 60 Mbyte/s in non-RAID mode and 35 MByte/s in RAID 5 mode.
The subsystem attaches to a PC server over the new SSA RAID adapter, which provides RAID 0, 1, 5 and non-RAID operation. Each subsystem enclosure holds up to five disk drives in "hot-swappable" bays for up to 22.5 GB of total non-RAID capacity.
IPL Systems' (Maynard MA 508-461-1000) RAIDTower II features dual controllers, Ultra SCSI and increased write cache. The controller has up to 64 MB of read cache and 32 MB of usable write cache, backed up by a mirrored battery. Each controller handles up to 28 drives per tower. Use up to 256 GB in the Enterprise Storage Series Enclosure.
More features: Simulated RAID 3 writing. Variable stripe sizing. Full redundancy back to the power source. Hot-pluggable, customer-replaceable controllers, disk drives, cooling fans and power supplies. Also available in a single controller configuration.
MicroNet Technology (Irvine, CA 714-453-6100) boosted the capacity of their lineup with the Ultra SCSI 9 GB hard disk drives. The drives offer sustained transfer rates up to 10 Mbyte/s, maximum data rates up to 40 Mbyte/s and access times as low as 7.9 ms. The drives complement MicroNet's recently released DataDock 7000, a high-end RAID 0/1/3/5 solution.
nStor (Lake Mary, FL 407-829-3500) has added two new products to their RAID solutions -- a high-performance RAID subsystem (the CR6e) and a 9 GB hard drive for the nStor CR8 RAID subsystem, which will double its storage capacity. The CR6e is meant for mission-critical apps and data storage on small to mid-size networks. The new drives let you daisy-chain subsystems together for as much as 750 GB of usable RAID 5 capacity. Great for companies investing in rackmount network components.
The CR6e, with its small footprint and hot-swappable cooling fans and power supplies, holds up to 24 GB. The new nStor one-channel AM RAID controller complies with Fast/Wide SCSI-2 SAF-TE (SCSI Accessed Fault-Tolerant Enclosures) specs. Advanced management software uses a GUI interface to provide monitoring and failure notification via network messaging and remote paging.
Optima Technology's (Irvine, CA 714-476-0515) dual-channel Ultra-Wide SCSI PCI adapter cards transfer data at up to 80 Mbyte/s when used in a RAID 0 configuration with Ultra SCSI hard disk drives. Optima will bundle these cards with their Fast/Wide SCSI-2 RAID bundles -- such as their DisKovery 8200W. These bundles can deliver transfer rates as high as 40 Mbyte/s using current SCSI-2 technology. The DisKovery 8200W PCI/Dual 8.2 GB array includes a dual channel Ultra-Wide SCSI PCI card and Optima DiskArray RAID software -- all for $3,700.
Raidtec (Roswell, GA 770-664-6066) debuted a 1 TB, 200 Mbyte/s fibre channel RAID storage system at Comdex. The new system comprises the Raidtec FibreArray subsystem, the Raidtec FibreRAID controller and 112 fibre channel 9 GB hard drives. The FibreArray subsystem features seven drive bays, three (N+1) power supplies and fans with hot replacement of each component. Cascade up to 16 FibreArrays to support up to 112 drives -- that's 1 TB off one FibreRAID-PCI controller.
Each FibreArray comes with Raidtec's "Environment Array Manager" (EAM). The EAM monitors and alarms drive, power, fans and temperature. It includes RAIDmanLITE, Raidtec's GUI disk array management software. Their FibreRAID-PCI controller supports RAID levels 0, 1, 0+1, 3, 5. Configuration is flexible.
You will pay about $32,000 for a typical 63 GB setup of FibreArray and FibreRAID-PCI controller.
Storage Computer Corporation (Nashua, NH 603-880-3005) boasts two new products aimed at open systems storage and data protection.
OmniRAID is data-configurable RAID with user-specified protection and performance levels. It offers concurrent RAID 0, 3, 5 and 7 on its Storage SuperServer family of shared storage devices.
The RAID 7 OmniForce is fully user customizable. Primary production sites can be multilevel mirrored, locally and/or remotely, to ensure "hot recovery" of critical data. Price: $30,000-$90,000 per license.
Storage Dimensions' (Milpitas, CA 408-954-0710) JETArray for Windows NT integrates high-speed image-based backup software, high-capacity DLT drives, RAID 0, 1, 0+1 or 5 protection and a resilient storage enclosure. The storage enclosure's 20 Mbyte/s backplane streams data to all the drives at once.
The enclosure features rugged "plug-in" tape modules, dual redundant power supplies, dual main power cords with cable lock guards and triple redundant cooling fans. Both power supplies and cooling fans are hot-swappable under load. The enclosure is rack-mountable. JETArray ranges from $24,000-$32,000.
Western Scientific (San Diego, CA 619-565-6699) offers their new CycloneRAID disk storage system with 3 1/2" 9.1 GB drives. It's expandable and scalable. Features: Hot-swappable drives. Auto-start. Hot spare disk drives. The system supports RAID 0, 3 and 5 simultaneously. To increase protection, configure it with redundant RAID controllers.
