Ramdisk Plus How-to

Perhaps no other type of server places the kinds of demands on the storage subsystem as database management. Although these servers contain built-in caches, other factors conspire to reduce their throughput. Even after optimizing database, index, query, and application design, the server may under-perform. Heavily loaded Microsoft SQL Server and Sybase database management servers enjoy increased throughput when deployed with RamDisk and/or SuperCache.

Microsoft SQL Server

The problem: Microsoft's SQL Server executes intermediate operations in a temporary database file called "tempdb". In many production environments, SQL Server"s overall performance is limited by the throughput of the resources associated with the tempdb file. When implementations place tempdb on a physical storage device, application throughput is typically restricted by that device. Although SQL Server provides a feature called "tempdb in RAM", the magnitude of performance gain when implementing this feature may be relatively small or non-existent.

The solution: RamDisk presents a powerful solution to this problem by providing up to 63 GB of virtual disk storage. SQL Server production environments with 8, 16 and 32 GB of system memory have dedicated 4, 12 and 20 GB to the RAM disk, and placed the tempdb file on the virtual disk. In these settings, accelerations in SQL Server application throughput of up to six times have been realized.

To implement this solution, SQL Server must be synchronized with the RAM disk's creation. To do this, the SQL Server service must be changed to manual start, and a start-up command added to RamDisk's SscAExec.bat file. Thereafter, SQL Server will be automatically started by the RamDisk service after the RAM disk is formatted and ready for use.

Web server performance issues: Effectively resolving performance issues on Web servers can be a complex task. There are a wide range of factors - both hardware and software - that contribute to a web site's overall performance. When resolving these issues, hardware solutions are generally the more expensive route. Before considering costly hardware solutions, carefully consider other areas of the web-site and the web applications and the improvements that may be realized there.

Some areas to address first: Source code optimization, HTTP compression and browser caching are three areas that merit attention. Using these means to reduce the size of each transfer, and to reduce the number of transfers, significantly larger server loads can be realized with the same hardware resources, and without impinging on performance.

dentifying hardware issues: Once these areas have been addressed, if server performance, especially under heavy loads, is still degraded, attention should be given to identifying a likely hardware bottleneck. Generally, this will be found in the network infrastructure, or in the storage subsystem, or both. Especially for web-sites handling high volumes of large content, the storage subsystem may impede overall server performance.

Storage performance solutions:RamDisk provide cost-effective solutions for web servers bottlenecked by their storage subsystems. Installing SuperVolume on the volume containing the HTTP service (typically the OS volume) yields accelerated server application performance with the required data persistence. Dynamic files, including web content and streaming data, may be stored on a RAM disk, essentially eliminating file access latencies.