Patent ID: 7363453
Filing Date: 2008-04-22
Classification: G06F,Y10S

Abstract:
1. A method of operating a storage system having storage devices on which logical volumes are stored according to an actual mapping, comprising: for each of a plurality of sampling intervals, collecting workload statistics for each of the logical volumes; for each of the storage devices, generating a respective first service time measure based on the actual mapping by (i) computing a service time for each of the sampling intervals from the workload statistics of the logical volumes of the storage device, (ii) identifying a set of highest service times from the service times computed over the sampling intervals, the set of highest service times not including all of the computed service times and (iii) computing a function of the set of highest service times; from the first service time measures of the storage devices, generating a hypothetical mapping that would result from a swap of logical volumes among a subset of the storage devices; for each of the subset of storage devices, generating a respective second service time measure by repeating steps (i)-(iii) based on the hypothetical mapping; comparing the second service time measures and first service time measures of the subset of storage devices to generate a service time improvement measure; and determining whether the service time improvement measure satisfies a predetermined service time improvement condition, and if so then performing the swap of logical volumes.