Accusys ExaRAID GUI - Manual (Page 28)

Introduction
1-3
• Support up to 32 disk groups and 32 logical disk per disk group
(Redundant/Upgradable controller)
• Support up to 24 disks in one chassis and totally 64 drives with expansion
units (Single controller)
• Support up to 24 disks in one chassis and totally 120 drives with
expansion units (Redundant/Upgradable controller)
• Volume management
• Support striping volume for performance enhancement
• Support concatenating volume for large-capacity LUN
• Support concatenated striping volume
• Online volume capacity expansion
• Online volume capacity shrink
• Support up to 32 volumes and 8 logical disks per volume
• Augmented RAID Features
• Flexible free chunk management
• Multiple RAID initializations: none, regular (write-zero), and background
• Support disk group write-zero initialization
• Support user-configurable disk group capacity truncation
• Support alignment offset
• Support intelligent computation for RAID data and parity
• Support fast read I/O response
• Support NVRAM-based write log and auto parity consistency recovery
• Support online bad block recovery and reallocation
• Support battery backup module (BBM) for data retention during no
power
• Caching and Performance Optimizations
• Selective cache unit sizes (KB): 4, 8, 16, 32, 64, and 128
• Independently-selectable caching policies for each LUN
• Selective pre-read options with pre-read depth
• Adaptive pre-read algorithms for sequential read workload
• Selective write caching policies: write-through and write-behind (delay
write)
• Selective cache flush period with manual flush utility
• Support intelligent write I/O merging and sorting algorithms