Accusys ExaRAID GUI - Manual (Page 174)

Advanced Functions
5-1
Chapter 5: Advanced Functions
5.1 Multi-Path IO Solutions
5.1.1 Overview
Multi-path IO allows a host computer to access a RAID system over
multiple paths for enhancing system availability and performance. The
RAID system supports multi-path IO either with the bundled proprietary
software or by the native multi-path IO software of the operating systems.
The following RAID systems support multi-path IO solutions:
• 4Gb/s FC-SAS/SATA RAID system
• 3Gb/s SAS-SAS/SATA RAID system
The single-controller systems support the following operating systems:
• Windows 2003 Server 32-bit/64-bit OS (PathGuard )
• Linux with 2.6.x series kernel, like SLES 9/10, RHAS 4/5, RHEL 4/5 (Device
Mapper multi-path driver).
• Solaris 10 OS (MpxIO, Multiplexed I/O)
• MAC OS X (default driver)
• VMWare ESX (default driver)
The dual-controller systems support the following operating systems:
• Windows 2003 Server 32-bit/64-bit OS (PathGuard )
• Linux with 2.6.x series kernel, like SLES 9/10, RHAS 4/5, RHEL 4/5 (Device
Mapper and proprietary multi-path driver).
For the updated interoperability list and the bundled multi-path software,
please contact your supplier.
5.1.2 Benefits
Below are the summarized benefits of the multi-path IO solution:
• Higher availability
With redundant paths, the failure of single path will not result in corruption
of the whole system, and the applications can continue to access the
storage devices without being aware of the path failures. This highly
enhances the availability of the whole system.
• Higher performance
The performance of single logical device will not be limited to the upper
bound of bandwidth provided by single path, and it is improved by
aggregating the bandwidth of multiple paths. It also outperforms host-