DEC-StorageWorks-RAID-SoftwareForOpenVMS

This document describes Digital's StorageWorks RAID Software for OpenVMS, a software-based solution designed to ensure data availability and enhance application performance.

Key Features and How it Works:

• RAID Technology: Coordinates multiple disk drives for data redundancy, ensuring data remains available even if one disk fails.
• Striping: Distributes data and I/O workload across multiple disk spindles to improve overall application performance and balance I/O load, minimizing "hot spots."
• Parity Plus Striping: Distributes "parity data" across the array, allowing for cost-effective data redundancy and reconstruction of a failed disk's data.
• Volume Shadowing Integration: For the highest combined performance and availability, it can be combined with Digital's Volume Shadowing for OpenVMS, which maintains multiple copies of data on redundant disks for 24x7 availability.
• Disk Partitioning: Allows subdividing arrays or individual disks into multiple "virtual disks" for easier storage management.

Benefits:

• High Data Availability: Keeps data accessible even if a disk in an array fails, preventing lost work and downtime.
• Enhanced Performance: Disk striping balances I/O load across spindles, significantly improving application performance.
• Cost-Effective: Provides data protection and performance enhancements at an affordable cost, especially with parity for redundancy.
• Investment Protection: Enables software-based RAID solutions on existing, older storage systems.
• Transparency: Multiple physical disks appear as a single "virtual" disk to applications and end-users.
• Productivity: Prevents time wasted re-doing work lost due to disk failures.

The software is presented as a flexible solution that can be tailored for different needs: mirroring for highest availability, striping for highest performance, and striped parity for cost-effective availability.