Nytro XD Overview : Theory of Operation

Theory of Operation

The Nytro XD solution uses a filter driver to review any storage I/O transaction destined for logical drives (also indicated as VDs) assigned to be cached.

*NOTE  Filter driver is the Nytro XD caching software.

Using its caching algorithms, Nytro XD determines hot region of frequent I/O activity, access data; the I/O activity is a continuous process; user activity might ramp up or applications might change. The address ranges are determined by the caching algorithms, and the write storage I/O transactions within this range is stored upon the Flash technology located on the Nytro WarpDrive card and also into the SAN or DAS storage. The read storage I/O transactions within the address range is quickly accessed from the Nytro WarpDrive. As the data within the cache cools, it is replaced with hotter data. The following table provides the different levels of hot region occurrence.

Level

Percentage of Hot Region

Percentage of Cold Region

Occurrence

1

0

100

At system start. No I/O to designated cache (WarpDrive).

2

Increasing with meaningful I/O

Decreasing

Performance increases as the cache filled hot region size increases. Based on the I/O rate.

3

100

0

Total available cache-full with actively read pages. Maximum hot region efficient for best performance, as long as the caching size does not exceed the available WarpDrive cache size. Best at available hardware configuration.