STORAGE SYSTEM
First Claim
Patent Images
1. A storage system comprising:
- a plurality of first storage devices; and
a first controller;
wherein the first controller;
provides a plurality of virtual volumes each composed of a plurality of virtual storage areas to a host computer coupled thereto;
manages a real pool composed of a plurality of real storage areas;
and when data transmitted from the host computer is received, the first controller;
allocates a real storage area unallocated to the plurality of virtual storage areas out of the plurality of real storage areas as an uncompressed real storage area to a virtual storage area where the data has been transmitted out of the plurality of virtual storage areas;
stores the data in the allocated real storage area;
if a real pool usage ratio, which is a rate of real storage areas allocated to the plurality of virtual storage areas out of the plurality of real storage areas constituting the real pool, exceeds a data compression start threshold set in advance,the first controller;
executes compression processing of the virtual volumes based on an order of compression target priority set respectively to the plurality of virtual volumes; and
stops execution of the compression processing if the real pool usage rate falls below a data compression end threshold set in advance.
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Abstract
The present invention relates to executing data compression based on the used capacities of real pools. The present storage subsystem stores a definition information regarding conditions of starting data compression and ending data compression defined via usage rates of a real pool as physical area, wherein if the usage rate of the real pool satisfies the condition for starting compression, the compression processing is started, and if the usage rate satisfies the condition for ending compression, the compression processing is ended.
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Citations
15 Claims
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1. A storage system comprising:
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a plurality of first storage devices; and a first controller; wherein the first controller; provides a plurality of virtual volumes each composed of a plurality of virtual storage areas to a host computer coupled thereto; manages a real pool composed of a plurality of real storage areas; and when data transmitted from the host computer is received, the first controller; allocates a real storage area unallocated to the plurality of virtual storage areas out of the plurality of real storage areas as an uncompressed real storage area to a virtual storage area where the data has been transmitted out of the plurality of virtual storage areas; stores the data in the allocated real storage area; if a real pool usage ratio, which is a rate of real storage areas allocated to the plurality of virtual storage areas out of the plurality of real storage areas constituting the real pool, exceeds a data compression start threshold set in advance, the first controller; executes compression processing of the virtual volumes based on an order of compression target priority set respectively to the plurality of virtual volumes; and stops execution of the compression processing if the real pool usage rate falls below a data compression end threshold set in advance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A storage system comprising:
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a plurality of storage devices constituting a basis for a real pool; and a first controller including a CPU;
whereinthe real pool is composed of a plurality of real storage areas; and the first controller provides a plurality of virtual volumes each composed of a plurality of virtual areas to computers coupled thereto, and when data transmitted from the computer is received, the first controller; allocates the real storage area unallocated to the plurality of virtual areas out of the plurality of real storage areas as an uncompressed real storage area to a virtual area where the data has been transmitted out of the plurality of virtual areas; stores the data in the allocated real storage area; if a real pool usage rate which is a ratio of real storage areas which are allocated to the plurality of virtual areas out of the plurality of real storage areas constituting the real pool exceeds a data compression start threshold set in advance, the first controller executes a compression processing including; specifying a virtual area storing uncompressed data out of the plurality of virtual areas of the virtual volume being the target of compression based on an order of compression target priority set respectively for the plurality of virtual volumes; executing data compression processing of the data stored in an uncompressed real storage area allocated to the specified virtual area; allocating to the specified virtual area a real storage area unallocated to the plurality of virtual areas out of the plurality of real storage areas as a compressed real storage area; storing to the compressed real storage area the data subjected to compression processing; cancelling allocation of the specified virtual area and the uncompressed real storage area allocated to the specified virtual area; and deleting data stored in the uncompressed real storage area; and stops the compression processing when the real pool usage rate falls below a compression end threshold set in advance; when the real pool usage rate falls below a data decompression start threshold set in advance; the first controller executes a decompression processing including; specifying a virtual area in which compressed data is stored out of the plurality of virtual areas of the virtual volume being the target of decompression based on an order of decompression target priority set respectively for the plurality of virtual volumes; executing data decompression processing of data stored in a compressed real storage area allocated to the specified virtual area; allocating a real storage area unallocated to the plurality of virtual areas out of the plurality of real storage areas as uncompressed real storage area to the specified virtual area; storing data subjected to decompression processing to the allocated uncompressed real storage area; cancelling allocation of the specified virtual area and the compressed real storage area allocated to the virtual area; and stops the data decompression processing when the real pool usage rate exceeds a data decompression end threshold set in advance; wherein the data compression processing or the data decompression processing will not be executed when any one of the following conditions A through C is satisfied, and an alert is output to a management computer coupled thereto; A. a load applied on the CPU is higher than a threshold set in advance; B. a specific function set in advance is being executed by the first controller;
orC. a load applied on the first storage device is higher than a threshold set in advance; wherein even when the real pool usage rate has exceeded the data compression start threshold, if the ratio of the compressed real storage areas with respect to storage areas already allocated to the plurality of virtual areas out of the plurality of real storage areas exceeds a threshold determined in advance, the compression processing is not executed, and an alert is output to a management computer coupled thereto; and the compression target priority of the virtual volume or the virtual area having a low access frequency is set high.
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Specification