I/O Bottlenecks

A key cause of I/O bottlenecks is fragmentation—the splitting of files into pieces to better utilize drive space. It is not uncommon for a file to be split into thousands or even tens of thousands of fragments—hence fragmentation has been an issue for the entire history of modern computing.

Condusiv’s IntelliWrite® technology optimizes I/O write operations, eliminating the performance penalties associated with the Windows OS splitting files into pieces and writing each piece to a different logical location within the SAN or NAS. IntelliWrite is aware of space allocation and aggregates writes to behave sequentially—requiring less I/O for every file written. Subsequent reads also benefit, since only minimum I/O is required to fulfill the request. As a result, only productive I/O requests are processed across the entire infrastructure, enabling more data to be processed in the same amount of time. When only productive I/O traffic is processed through the server, network and storage, I/Os per second are accelerated, latency is greatly reduced, and more work can be performed in the same amount of time. This greatly improves the efficiency of physical servers for increased bandwidth.

IntelliWrite prevents the Windows OS from storing files as disjointed block sets in its logical block space representation of a logical storage volume. In a virtualized environment, the problem of excessive, unnecessary I/O is compounded as multiple VMs share the same storage resource, resulting in highly random I/O behavior pushed down to the disk subsystem. To solve this, IntelliWrite adds intelligence to the way the Windows OS preallocates file space in order to continuously restructure writes in a coherent manner, store files as contiguous sets of blocks, and prevent performance penalties.