Patent ID: 9280300
Filing Date: 2016-03-08
CPC Classification: G06F

Claim Text:
1. A method for dynamically managing placement of blocks of a logical file between a flash storage tier and a hard disk (HDD) storage tier, the method comprising: collecting, by a computer system for a current time interval in a plurality of time intervals, I/O statistics pertaining to the logical file, wherein a first subset of the blocks of the logical file are stored on the flash storage tier, and wherein a second subset of the blocks of the logical file are stored on the HDD storage tier; generating, by the computer system for the current time interval, a heat map for the logical file based on the I/O statistics, the heat map indicating, for each block of the logical file, a number of times the block has been accessed during the current time interval; retrieving, by the computer system, one or more other heat maps for the logical file that were generated by the computer system for one or more time intervals in the plurality of time intervals prior to the current time interval; identifying, by the computer system using the heat map and the one or more other heat maps, one or more of the blocks of the logical file as being performance-critical blocks, wherein the identifying comprises, for each time interval in the plurality of time intervals: for each block of the logical file: retrieving, from the heat map corresponding to the time interval, the number of times the block was accessed during the time interval; and calculating a temperature value for the block based on said number, wherein the temperature value is further scaled based on a temporal position of the time interval in the plurality of time intervals, moving, by the computer system, data between the flash storage tier and the HDD storage tier such that the one or more performance-critical blocks are placed on the flash storage tier.