Storage system
First Claim
1. A storage system comprising:
- a processor;
a plurality of first storage devices providing a first tier; and
a plurality of second storage devices providing a second tier whose performance is lower than the first tier,wherein the processor is programmed to;
provide a virtual volume whose data is stored in a plurality of tiers including the first tier and the second tier according to a first threshold value based on whether an access frequency of stored data in a predetermined period is higher than the first threshold value;
migrate first data stored in the second tier to the first tier in a case where an access frequency of the first data in the predetermined period is higher than the first threshold value; and
migrate the first data stored in the second tier to the first tier in a case where an access frequency of the first data in a period shorter than the predetermined period is higher than a second threshold value,wherein the second threshold value is higher than the first threshold value.
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Abstract
A storage system monitors the first access frequency of occurrence which is the access frequency of occurrence from a host device during a first period, and the second access frequency of occurrence which is the access frequency of occurrence from a host device during a second period shorter than the first period. Along with performing data relocation among the tiers (levels) in the first period cycle based on the first access frequency of occurrence, the storage system performs a decision whether or not to perform a second relocation based on the first access frequency of occurrence and the second access frequency of occurrence, synchronously with access from a host device. Here the threshold value utilized in a decision on whether or not to perform the first relocation is different from the threshold value utilized in a decision on whether or not to perform the second relocation.
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Citations
15 Claims
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1. A storage system comprising:
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a processor; a plurality of first storage devices providing a first tier; and a plurality of second storage devices providing a second tier whose performance is lower than the first tier, wherein the processor is programmed to; provide a virtual volume whose data is stored in a plurality of tiers including the first tier and the second tier according to a first threshold value based on whether an access frequency of stored data in a predetermined period is higher than the first threshold value; migrate first data stored in the second tier to the first tier in a case where an access frequency of the first data in the predetermined period is higher than the first threshold value; and migrate the first data stored in the second tier to the first tier in a case where an access frequency of the first data in a period shorter than the predetermined period is higher than a second threshold value, wherein the second threshold value is higher than the first threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15)
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11. A method of controlling a storage system having a processor, a plurality of first storage devices providing a first tier, and a plurality of second storage devices providing a second tier whose performance is lower than the first tier, the method being performed by the processor comprising:
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providing a virtual volume whose data is stored in a plurality of tiers including the first tier and the second tier according to a first threshold value based on whether an access frequency of stored data in a predetermined period is higher than the first threshold value; migrating first data stored in the second tier to the first tier in a case where an access frequency of the first data in the predetermined period is higher than the first threshold value; and migrating first data stored in the second tier to the first tier in a case where an access frequency of the first data in a period shorter than the predetermined period is higher than a second threshold value, wherein the second threshold value is higher than the first threshold value.
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Specification