Program and apparatus for balancing activity of disk storage devices in response to statistical analyses and preliminary testing
AssigneeEMC Corporation
InventorEitan Bachmat
Life of this patent
Estimating the term…
Abstract
Load balancing of activities on physical disk storage devices is accomplished by monitoring reading and writing operations to logical volumes on the physical disk storage devices. A list of exchangeable pairs of logical volumes is developed based on size and function. Statistics accumulated over an interval are then used to obtain access activity values for each logical volume and each physical disk drive. A statistical analysis selects one logical volume pair. After testing to determine any adverse effect of making that change, the exchange is made to more evenly distribute the loading on individual physical disk storage devices.
Claims22
A method for use in balancing activity on a plurality of disk storage devices wherein at least two of the disk storage devices are divided into plural logical volumes and wherein a performance monitor retrieves read and write disk access statistics for each logical volume, said method comprising:
- A. compiling a list of all pairs of exchangeable logical volumes on the disk storage devices, each exchangeable pair being constituted by two logical volumes that are capable of swapping the data stored therein,
- B. selecting a configuration of a logical volume pair on the disk storage devices based upon the compiled statistics from the performance monitor, and
- C. exchanging the data stored in the selected pair of exchangeable logical volumes on the disk storage devices.
Apparatus for balancing activity on a plurality of disk storage devices that are divided into plural logical volumes of predetermined sizes and of predetermined functional characteristics, said load balancer comprising:
- A. means for gathering read and write disk access statistics for each logical volume over a time interval, each exchangeable pair being constituted by two logical volumes that are capable of swapping the data stored therein,
- B. a program for determining appropriate reallocations of logical volumes for balancing loads including:
- i. means for compiling a list of exchangeable logical volume pairs based upon the size and functional characteristics of the logical volumes,
- ii. means for selecting a configuration of the disk storage devices based upon exchanges of the logical volume pairs list that minimizes imbalance in activity based upon the compiled statistics, and
- C. means for testing the effect of the selected exchanges whereby said program identifies a logical volume pair for which logical volumes should be exchanged, and
- D. means exchanging the logical volumes in the identified logical volume pair.
Dependencies are inferred from the claim text.