Abstract
The invention relates generally to mass storage systems, and in particular to mass storage systems in which stored logical volumes are duplicated in mirrored form. The system includes a method for dynamically maximizing separation of said logical volumes by adjusting the mirror service policy for a disk drive system. Statistics are periodically collected describing the reading and writing of data to mirrored logical volumes of the system in successive time periods and, from time to time, based upon the collected statistics, activity levels for the logical volumes are determined. A matching algorithm, weighted or unweighted, maximizes separation of the logical volumes and minimizes average physical drive seek times. In particular, the system takes into account activity levels at the physical devices and results in more efficient accessing of logical volume pairs as well as a better balance or loading of logical volumes.
| Original language | English |
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| Patent number | US6775739 |
| IPC | G06F 12/ 16 A I |
| Priority date | 10/04/98 |
| State | Published - 10 Aug 2004 |