Although the focus of our tests was hardware-based RAID (i.e., subsystems that use a dedicated RAID controller), if you've already invested in storage and don't have $10,000 or so to spend on a RAID subsystem, there are many software applications on the market that let you configure your existing disk storage as a RAID array. These software programs perform RAID calculations with the help of your server's CPU rather than relying on a dedicated RAID controller.
For a NetWare environment:
Corel ((613) 728-8200; fax (613) 728-9790) offers Corel SCSI Network Manager with CorelRAID 2.0 for $595. CorelRAID uses either RAID 4 or 5, can support a maximum of 16 drives, and supports the hot swapping of drives and a hot spare. Under NetWare, you can define users and groups to receive message
s if a drive failure occurs. To use CorelRAID, you need a PC-compatible 386 server running NetWare 3.1x or higher, 4 MB of RAM, three SCSI hard drives, and a SCSI host adapter with ASPI (advanced SCSI programming interface).
For an OS/2 environment:
Cyranex ((613) 738-3864; fax (613) 738-3871), formerly Pro Engineering, offers two software RAID packages for OS/2: EZRAID Pro for $795 or EZRAID Lite for $195. You can use EZRAID Pro with OS/2 version 2 or higher; it will work with SCSI, IDE, ESDI, and other types of hard drives and host adapters, although Cyranex recommends using SCSI devices. You can mix different drive types and host adapters within the same array. A minimum of two hard drives is required. EZRAID Pro supports RAID 0, 1, 4, or 5, supports hot sparing, and has a remote failure notification utility and performance monitor. EZRAID Lite is designed to be used with OS/2 desktop systems only and supports RAID 0 and 1. It also supports hot sparing and comes with a perf
ormance monitor utility.
For a Unix environment:
Veritas Software ((415) 335-8000; fax (415) 335-8050) offers VxVM (Veritas Volume Manager) 2.0, which supports RAID 0, 1, and 5 with hot spare drives. VxVM 2.0 has a GUI for such on-line disk administration tasks as monitoring disk usage and fine-tuning to handle I/O bottlenecks. VxVM costs $1500 for desktop systems and starts at $3500 for desktop servers.
A Highly Capable RAIDing Party
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Software from Corel, Cyranex, and Veritas offers an inexpensive RAID alternative.
Software RAID Solutions
