High Speed Caching

High-speed caching can significantly increase the performance of some applications, particularly databases, that perform large amounts of disk I/O. High Speed Caсhing operates on the principle that server memory is faster than disk. The memory cache stores data that is more likely to be required by applications. If a program turns to the disk for data, a search is first made for the relevant block in the cache. If the block is found the program uses it, otherwise the data from the disk is loaded into a new block of memory cache.

Disk caching can operate in two modes: write-through and write-back. In the first case, as application data in the memory cache changes, updating of the corresponding disk block happens immediately. In write-back mode, updates of data on disk occur only when the contents of unused blocks of memory are supplanted from the cache.

Write-back mode is distinguished by better performance, but data integrity may be compromised by system failure.

Cache size in StarWind is limited only by the amount of RAM installed in each server node, and since StarWind installs on any standard Windows compatible x86 server increase cache is as affordable as adding more memory. StarWind iSCSI SAN support for High Speed Caching provides a scalable solution that can keep up with the most demanding applications.