Cache - Accusys ExaSAN User Manual

Controller Cache – Check this box to enable the controller cache. This speeds up the data
transfer to and from the disks.
Caution
Data in cache may be erased if power down unexpected. Suggest
using a UPS (uninterruptible power supply) to prevent this scenario.
Synchronize Cache – Check this box to enable cache synchronization with drives, to ensure all
write data is correct, there is a frequently latency time within. For video capture, disable
synchronization, because the video capture needs to be able to constantly write data to the
RAID storage without long latency.
Read Pre-fetch – Identifies sequential access patterns and aggressively pre-fetches patters
into cache. From the drop down list, choose the number of stripes to pre-fetch. The default is
32; this is the recommended number.
Drive Cache – Choose which drives to cache. When more than one application accesses the
database, the first applications cache needs to synchronize with the second. Each drive
contains a built in write cache; checking these boxes chooses which drives to enable the
caching on. Caching improves the efficiency and speed of data transfer.
All Drives Cache On/All Drives Cache Off – Click this button to enable/disable the caching on
for all available drives.
User Guide

4.1.6.6 Cache

5. RAID