We offer RS/6000-compatible external RAID in Ultra-Wide (40 MB/sec), Ultra2-Wide (80 MB/sec) and Ultra-160 (160 MB/sec) in both rackmount and tower configurations. Capacities range from 12 GB in RAID0 and 8 GB in RAID5 to about 1 TB in single enclosures with single or redundant RAID controllers. Prices are custom quoted and can range from under US$1,000 for a small unit to under US$15,000 for a high-end unit. In some cases configurations can be built using some or all pre-owned parts, which can result in very functional and affordable RAID priced toward the lower end of the price range.

In building RAID subsystems we use:

• Kingston/StorCase enclosures and removable drive assemblies
• Infortrend or Kingston/Storcase RAID controllers
• IBM SCSI disk drives

We can also work with Seagate disk drives and other brands of RAID controllers.

	Data Silo Expansion Chassis Overview The Data Silo® family of expansion chassis consists of rugged and reliable stand-alone external storage enclosures for housing 3.5 inch and 5.25 inch full or half-height SCSI or IDE devices, including StorCase's Data Express removable frame and carrier units. FIREWIRE/IDE RAID   DS322 Rack Mount   SCSI/IDE RAID DS560 Rack Mount DS570 Rack Mount SCSI/SCSI DS351 Rack Mount DS320 Rack Mount DS100 1, 2 & 4-Bay DS400 JBOD Rack Mount DS400 JBOD Tower DS550 RAID Tower DS550 RAID Rack Mount

Physical size and packaging can range from a 4-bay tabletop unit capable of 8-300 GB to a 12-bay rackmount or tower unit capable of up to about 1 TB. In some cases it may be desirable to package a high-capacity tape drive (DDS-3, DDS-4, DLT or tape library) in the same or another enclosure for realistic backup/restore times.

Drive sizes range from 4.5 GB to 146 GB. RAID configurations may be partitioned or not as the operating environment requires. Direct conversion of VS application environments to unix and COBOL ReSource may call for partitioning in order to have multiple VS volume names expected by existing procedures and programs. Multiple VS volume names may be created with or without partitioned disk space. If partitioned, volumes are protected from using each other's space. Otherwise multiple volumes can draw from the same disk space or from several pools of disk space, thus avoiding "full volume" problems common in the VS environment.

Most of the RAID controller models we use can accept 64 MB or 128 MB of cache memory. Some new U160 and U320 models can go up to 1 GB. We recommend filling out cache to its maximum to gain the most benefit from the RAID subsystem. The more hardware cache that is used, the more the disk subsystem behaves like an all-solid-state disk.

All models of RAID controller we employ use an async connection for management while some support in-band and PPP management. Unix environments usually require using async for RAID management.

We have built and deployed a number of RAID subsystems that are in production use as you read this page. We also use RAID on most of our internal systems. You can be confident that we can provide you with the best in storage solutions.

Contact us for more information.