Method for performing on-line reconfiguration of a disk array concurrent with execution of disk I/O operations
First Claim
1. In a computer system including an array of disk drives for use in storing information comprising one of data and parity, a method for reconfiguring stored information between a first disk array configuration and a second disk array configuration, comprising the steps of:
- providing a predetermined number of disk drives in said array of disk drives, with said predetermined number of disk drives being all of said disk drives in said array of disk drives;
transferring information to all of said predetermined number of disk drives for storage therein in accordance with said first disk array configuration, wherein said information includes data that is stored in a plurality of said predetermined number of disk drives;
deciding to reconfigure said information from said first disk array configuration to said second disk array configuration;
wherein said first disk array configuration includes at least one of;
(a) a RAID level selected from a group that includes one or more of the following;
RAID levels 0, 1, 2, 3, 4, and 5; and
(b) a first plurality of stripes for storing the information and having a first size;
wherein said second disk array configuration includes at least one of;
(i) a RAID level selected from a group that includes one or more of the following;
RAID levels 0, 1, 2, 3, 4, and 5, and being different from said RAID level selected for said first disk array configuration and (ii) a second plurality of stripes for storing information and having a second size that is different from said first size of said first disk array configuration;
reconfiguring said information from said first disk array configuration to said second disk array configuration during a single reconfiguration using said same predetermined number of disk drives that are used in said transferring information step, wherein said reconfiguring step includes;
reading said information from said same predetermined number of disk drives according to said first disk array configuration; and
writing said information from said reading information step to said same predetermined number of disk drives according to said second disk array configuration.
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Accused Products
Abstract
An architecture for on-line reconfiguration on a RAID level 0, 1, 2, 3, 4 or 5 disk array. This architecture allows the computer system to perform reconfiguration of the disk array transparently, with disk I/O operations being performed concurrently with reconfiguration operations. The reconfiguration process allocates computer system resources necessary to support both the old and new array configurations during the reconfiguration process. Logical areas within the array are sequentially reconfigured from the old configuration to the new configuration. Data in each logical area is read from the area undergoing reconfiguration and thereafter overwritten in accordance with the new array configuration. System I/O requests received during reconfiguration which are directed to unreconfigured areas in the disk array are executed in accordance with the old array configuration. System I/O requests received during reconfiguration which are directed to reconfigured areas in the disk array are executed in accordance with the new array configuration.
166 Citations
11 Claims
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1. In a computer system including an array of disk drives for use in storing information comprising one of data and parity, a method for reconfiguring stored information between a first disk array configuration and a second disk array configuration, comprising the steps of:
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providing a predetermined number of disk drives in said array of disk drives, with said predetermined number of disk drives being all of said disk drives in said array of disk drives; transferring information to all of said predetermined number of disk drives for storage therein in accordance with said first disk array configuration, wherein said information includes data that is stored in a plurality of said predetermined number of disk drives; deciding to reconfigure said information from said first disk array configuration to said second disk array configuration; wherein said first disk array configuration includes at least one of;
(a) a RAID level selected from a group that includes one or more of the following;
RAID levels 0, 1, 2, 3, 4, and 5; and
(b) a first plurality of stripes for storing the information and having a first size;wherein said second disk array configuration includes at least one of;
(i) a RAID level selected from a group that includes one or more of the following;
RAID levels 0, 1, 2, 3, 4, and 5, and being different from said RAID level selected for said first disk array configuration and (ii) a second plurality of stripes for storing information and having a second size that is different from said first size of said first disk array configuration;reconfiguring said information from said first disk array configuration to said second disk array configuration during a single reconfiguration using said same predetermined number of disk drives that are used in said transferring information step, wherein said reconfiguring step includes; reading said information from said same predetermined number of disk drives according to said first disk array configuration; and writing said information from said reading information step to said same predetermined number of disk drives according to said second disk array configuration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A computer system comprising:
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an array of disk drives for storing information comprising at least one of data and parity; and means for reconfiguring said information stored within said disk drives from a first configuration to a second configuration, wherein said means for reconfiguring includes reading means for reading said information stored within said disk drives according to said first configuration and writing means for writing said information that was read using said reading means to said disk drives according to said second configuration; wherein said first configuration includes at least one of;
(a) a RAID level selected from a group that includes one or more of the following;
RAID levels 0, 1, 2, 3, 4, and 5; and
(b) a first plurality of stripes for storing information and having a first size, andsaid second configuration includes at least one of;
(i) a RAID level selected from a group that includes one or more of the following;
RAID levels 0, 1, 2, 3, 4, and 5, and being different from said RAID level selected for said first configuration and (ii) a second plurality of stripes for storing information and having a second size that is different from said first size of said first configuration. - View Dependent Claims (10, 11)
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Specification