Compaq 307560-001 Novell GroupWise Performance Management on Compaq Servers - Page 21

ECG007.0897 WHITE PAPER (cont.) 2...1 The Array Accelerator also anticipates requests as another method of increasing performance. A multi-threaded algorithm is used to predict the read operation most likely for the array. That prediction is used to pre-read data into the Array Accelerator so that data may be there before you access it. If the Smart-2 Controller receives a request for cached data, it can be burst into system memory at PCI or EISA bus speeds. NetWare Operating System Tuning SET Read-Ahead Cache A GroupWise Server tunable parameter that impacts the system performance is the Read Ahead Cache which is the amount of memory allocated to the GroupWise Server specified in bytes. Novell and Compaq engineers recommend using the default read-ahead cache due to the 15-20% performance gain show in the following figure. Performance of Novell Read Ahead Cache Response Time (Seconds) 1200 1000 800 600 400 200 0 Enable Disable Enable or Disable the feature Figure 8. Performance of Novell Read Ahead Cache SET Packet Receive Buffers Another GroupWise Server tunable parameter that impacts system performance is Packet Receive Buffers. The more packet receive buffers a system has, the better the server's performance; however, these buffers use system memory needed by processes, so you must balance buffer allocation against available memory. The server automatically adjusts the allocation of buffers between minimum and maximum. The server will allocate more buffers to handle the load. Over time, it will reach an optimum setting that provides the best performance; however, some performance degradation will occur during the system ramp-up. Novell and Compaq engineers preset the packet receive buffers to an optimum setting and yielded a 10-15% performance gain. Therefore, our recommendation is to use the MONITOR to determine what the server's dynamic allocation of Packet Receive Buffers, and change that parameter to what the server dynamically configured.