Compaq ProLiant 1000 Configuration and Tuning of Sybase System 11 for NetWare - Page 9

Configuration and Tuning of Sybase System 11 for NetWare on Compaq Servers Page 5 For dedicated Sybase SQL Servers leave at least 10% of the original cache buffers as free cache buffers. For non-dedicated Sybase SQL Servers leave at least 20% of the original cache buffers as free cache buffers. Free cache buffers are reported as total cache buffers by the NetWare Monitor utility. Dedicated server: 130561 original cache buffers - 80384 System 11 buffers - 13056 free cache buffers = 37121 buffers remaining Non-dedicated server: 130561 original cache buffers - 80384 System 11 buffers - 26112 free cache buffers = 24065 buffers remaining If the number of buffers remaining is negative you will need to increase the amount of memory in the server or reduce the memory allocations for Sybase System 11and run at a less than optimal performance level. If the number of buffers remaining is positive you may want to increase the value for the Sybase sp_configure total memory parameter. Remember a NetWare buffer is 4 KB in size and a Sybase page is 2 KB in size. Disk Subsystem Planning The objective of this section is to provide information on the benefits of the Compaq SMART and SMART-2 SCSI Array Controller Array Accelerator and the pros and cons of various fault tolerance methods. Additional information on disk subsystem configuration and Compaq drive array technology can be found in the following manuals: s Configuring Compaq RAID Technology for Database Servers, Compaq TechNote, P/N 184206-001 s Compaq SMART-2 Array Controller User Guide, P/N 184482-001 s Compaq SMART SCSI Array Controller User Guide, P/N 142136-004 s Sybase SQL Server System Administration Guide, Doc. ID 32500-01-1100-00 Array Accelerator: Its Function and Benefit in a Sybase SQL Server Environment The Array Accelerator is a feature of the SMART and SMART-2 SCSI Array Controllers. The main function of the Array Accelerator is to boost performance of disk operations by storing data in the cache memory on the controller. The SMART SCSI Array controllers has 4MB of cache that is mirrored, yielding 2MB of usable cache memory. The SMART-2 Array controller has 4MB of ECC (Error Checking and Correcting) memory as cache memory. The Array Accelerator is shared among all logical drive volumes configured on the controller, and can be enabled/disabled on a per-logical-volume basis. SMART and SMART-2 SCSI Array Controller characteristics On the SMART controller, the Array Accelerator functions as write cache only, while the SMART-2 controller has an added feature that allows the Array Accelerator to function as write cache, read-ahead cache, or a combination of both. With the added feature of the SMART-2 controller, you can, for example, configure the Array Accelerator on the particular controller to function as 50% read-ahead and 50% write cache. Then every logical volume on this controller is supported by the Array Accelerator in the 50/50 mode. The only exception is when the Array Accelerator is disabled for the volume. Again, with the SMART controller, only writes can be cached; there is no read-ahead option. © 1996 Compaq Computer Corporation, All Rights Reserved Doc No 140A/0896