Multi-environment data consistency
First Claim
Patent Images
1. A method for maintaining the consistency of data across storage devices, comprising:
- receiving a user specified cut-off time value in a command to ensure that data is consistent as of the user specified cut-off time by receiving at least one user specified volume pair to which the user specified cut-off time applies, wherein a volume pair comprises a volume in a first storage device and a corresponding volume in a second storage device, wherein the volume in the second storage device includes a copy of data in the corresponding volume in the first storage device;
obtaining information on data writes to the first storage device, including information on time stamp values associated with the data writes indicating an order of the data writes to the first storage device;
forming at least one group of data writes having time stamp values earlier in time than the user specified cut-off time value, wherein the steps of obtaining the information and forming groups of data writes are performed multiple times to form multiple groups of data writes having time stamp values earlier in time than the user specified cut-off time value;
forming a group of data writes having time stamp values later in time than the user specified cut-off time value;
transferring the data writes in the groups having time stamp values earlier in time than the user specified cut-off time value to the second storage device for storage therein;
suspending for a time period transfers of data writes to the user specified volumes in the second storage device after forming the group of data writes having time stamp values later in time than the user specified cut-off time value and after transferring data writes from the groups having time stamp values earlier in time than the user specified cut-off time value to the second storage device; and
performing analysis of data in the second storage device during the time period.
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Abstract
Disclosed is a system for maintaining consistency of data across storage devices. A cut-off time value is provided to the system. The system then obtains information on data writes to a first storage device, including information on time stamp values associated with the data writes indicating an order of the data writes to the first storage device. At least one group of data writes having time stamp values earlier in time than the cut-off time value is then formed. The system then transfers the data writes in the groups to a second storage device for storage therein.
117 Citations
15 Claims
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1. A method for maintaining the consistency of data across storage devices, comprising:
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receiving a user specified cut-off time value in a command to ensure that data is consistent as of the user specified cut-off time by receiving at least one user specified volume pair to which the user specified cut-off time applies, wherein a volume pair comprises a volume in a first storage device and a corresponding volume in a second storage device, wherein the volume in the second storage device includes a copy of data in the corresponding volume in the first storage device;
obtaining information on data writes to the first storage device, including information on time stamp values associated with the data writes indicating an order of the data writes to the first storage device;
forming at least one group of data writes having time stamp values earlier in time than the user specified cut-off time value, wherein the steps of obtaining the information and forming groups of data writes are performed multiple times to form multiple groups of data writes having time stamp values earlier in time than the user specified cut-off time value;
forming a group of data writes having time stamp values later in time than the user specified cut-off time value;
transferring the data writes in the groups having time stamp values earlier in time than the user specified cut-off time value to the second storage device for storage therein;
suspending for a time period transfers of data writes to the user specified volumes in the second storage device after forming the group of data writes having time stamp values later in time than the user specified cut-off time value and after transferring data writes from the groups having time stamp values earlier in time than the user specified cut-off time value to the second storage device; and
performing analysis of data in the second storage device during the time period.
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2. A method for maintaining the consistency of data across storage devices, comprising:
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receiving a user specified cut-off time value in a command to ensure that data is consistent as of the user specified cut-off time obtaining information on data writes to a plurality of primary storage devices by a plurality of controllers, including information on time stamp values associated with the data writes indicating an order of the data writes to the at least one primary storage device;
forming at least one group of data writes having time stamp values earlier in time than the user specified cut-off time value by;
(i) determining a maximum time stamp value for the data writes to the plurality of controllers;
(ii) determining a minimum value of the maximum time stamp values;
(iii) forming a first group including data writes to the plurality of controllers having time stamp values earlier in time than the minimum value after determining that the minimum value is earlier in time than the user specified cut-off time value; and
(iv) forming a second group including data writes to the plurality of controllers having time stamp values earlier in time than the minimum value and a third group including data writes having time stamp values later in time than the user specified cut-off time after determining that the minimum value is later in time than the user specified cut-off time value; and
transferring the data writes in the groups to a secondary storage device for storage therein.
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3. A method for maintaining the consistency of data across storage devices, comprising:
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receiving a user specified cut-off time value in a command to ensure that data is consistent as of the user specified cut-off time;
obtaining information on data writes to a first storage device, including information on time stamp values associated with the data writes indicating an order of the data writes to the first storage device;
forming at least one group of data writes having time stamp values earlier in time than the user specified cut-off time value, wherein the steps of obtaining the information and forming groups of data writes are performed multiple times until the time stamp value is determined to be at or later in time than the user specified cut-off time value;
calculating a time stamp value by adding a predetermined time value to the time stamp value of a previously formed group of data writes after determining that there were no data writes to the first storage device since a previous instance of obtaining information; and
transferring the data writes in the groups to a second storage device for storage therein. - View Dependent Claims (4, 5)
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6. A system for maintaining the consistency of data across storage devices, comprising:
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a processing unit;
a first storage device;
a second storage device;
a memory area for storing at least one data structure for access by program logic being executed by the processing unit, including;
(i) a user specified cut-off time value, received in a command to ensure that data is consistent as of the user specified cut-off time;
(ii) information on a group of data writes to the first storage device, including information on time stamp values associated with the data writes indicating an order of the data writes to the first storage device, wherein the time stamp values of the data writes in the group are earlier in time than the user specified cut-off time value, and wherein the data-writes-in the-group are transferred to the second storage device for storage therein;
(iii) information on at least one user specified volume pair to which the user specified cut-off time applies received in the command, wherein a volume pair comprises a volume in the second storage device and a corresponding volume in the first, storage device, wherein the volume in the second storage device includes a copy of data in the corresponding volume in the first storage device; and
(iv) information on a group of data writes having time stamp values later in time than the user specified cut-off time value;
means for suspending for a time period transfers of data writes to the user specified volumes in the second storage device after forming the group of data writes having time stamp values later in time than the user specified cut-off time value and after transferring data writes from the groups having time stamp values earlier in time than the user specified cut-off time value to the second storage device; and
means for performing analysis of data in the second storage device during the time period. - View Dependent Claims (7, 8)
a first long distance communication line providing communication between the host system and the first processing unit; and
a second long distance communication line providing communication between the host system and the second storage device.
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9. A system for maintaining the consistency of data across storage devices, comprising:
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a host system including a processing unit;
a plurality of primary storage devices;
a secondary storage device;
a plurality of controllers controlling access to the primary storage devices, wherein the host system queries the plurality of controllers to obtain information on the data writes to the primary os storage devices, and wherein the host system transfers data writes to the secondary storage device by reading the data writes from the plurality of controllers and transferring the data writes to the secondary storage;
a memory area for storing at least one data structure for access by program logic being executed by the processing unit, including;
(i) a user specified cut-off time value, received in a command to ensure that data is consistent as of the user specified cut-off time;
(ii) information on a group of data writes to the primary storage devices, including information on time stamp values associated with the data writes indicating an order of the data writes to the primary storage devices, wherein the time stamp values of the data writes in the group are earlier in time than the user specified cut-off time value, and wherein the data writes in the group are transferred to the secondary storage device for storage therein, (iii) data indicating a maximum time stamp value for data writes to the plurality of controllers;
(iv) data indicating a minimum value of the maximum time stamp values;
(v) data indicating a first group of data writes to the plurality of controllers having time stamp values earlier in time than the minimum value after determining that the minimum value is earlier in time than the user specified cut-off time value; and
(vi) data indicating a second group including data writes to the plurality of controllers having time stamp values earlier in time than the minimum value and data indicating a third group including data writes having time stamp values later in time than the user specified cut-off time after determining that the minimum value is later in time than the user specified cut-off time value.
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10. A system for maintaining the consistency of data across storage devices, comprising:
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a host system including a processing unit;
a first storage device;
a second storage device;
a first controller, wherein the first controller controls access to the first storage device, wherein the host system queries the first controller to obtain information on the data writes to the first storage device, and wherein the host system transfers data writes to the second storage device by reading the data writes from the first controller and transferring the data writes to the second storage device;
a memory area for storing at least one data structure for access by program logic being executed by the processing unit, including;
(i) a user specified cut-off time value, received in a command to ensure that data is consistent as of the user specified cut-off time;
(ii) information on a group of data writes to a first storage device, including information on time stamp values associated with the data writes indicating an order of the data writes to the first storage device, wherein the time stamp values of the data writes in the group are earlier in time than the cut-off time value, and wherein the data writes in the group are transferred to a second storage device for storage therein;
(iii) data indicating a calculated time stamp determined the program logic adding a predetermined time value to the time stamp value of a previously formed group of data writes after determining that there were no data writes to the first storage device since a previous instance of obtaining information.
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11. An article of manufacture for use in programming a processing unit to transfer data between a first storage device and a second storage device, the article of manufacture comprising at least one computer readable storage device including at least one computer program embedded therein that causes the processing unit to perform:
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receiving a user specified cut-off time value in a command to ensure that data is consistent as of the user specified cut-off time receiving at least one user specified volume pair to which the user specified cut-off time applies, wherein a volume pair comprises a volume in the first storage device and a corresponding volume in the second storage device, wherein the volume in the second storage device includes a copy of data in the corresponding volume in the first storage device;
obtaining information on data writes to the first storage device, including information on time stamp values associated with the data writes indicating an order of the data writes to the first storage device;
forming at least one group of data writes having time stamp values earlier in time than the user specified cut-off time value, wherein the steps of obtaining the information and forming groups of data writes are performed multiple times to form multiple groups of data writes having time stamp values earlier in time than the user specified cut-off time value;
forming a group of data writes having time stamp values later in time than the user specified cut-off time value;
transferring the data writes in the groups having time stamp values earlier in time than the user specified cut-off time value to the second storage device for storage therein;
suspending for a time period transfers of data writes to the user specified volumes in the second storage device after forming the group of data writes having time stamp values later in time than the user specified cut-off time value and after transferring data writes from the groups having time stamp values earlier in time than the user specified cut-off time value to the second storage device; and
performing analysis of data in the second storage device during the time period.
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12. An article of manufacture for use in programming a processing unit to transfer data writes from a plurality of controllers directed toward primary storage devices to a secondary storage device, wherein data writes are made to a plurality of controllers, the article of manufacture comprising at least one computer readable storage device including at least one computer program embedded therein that causes the processing unit to perform:
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receiving a user specified cut-off time value in a command to ensure that data is consistent as of the user specified cut-off time;
obtaining information on data writes to the plurality of controllers, including information on time stamp values associated with the data writes indicating an order of the data writes to the primary storage devices;
forming at least one group of data writes having time stamp values earlier in time than the user specified cut-off time value by;
(i) determining a maximum time stamp value for the data writes to the plurality of controllers;
(ii) determining a minimum value of the maximum time stamp values;
(iii) forming a first group including data writes to the plurality of controllers having time stamp values earlier in time than the minimum value after determining that the minimum value is earlier in time than the user specified cut-off time value; and
(iv) forming a second group including data writes to the plurality of controllers having time stamp values earlier in time than the minimum value and a third group including data writes having time stamp values later in time than the user specified cutoff time after determining that the minimum value is later in time than the user specified cut-off time value;
transferring the data writes in the groups to the secondary storage device for storage therein.
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13. An article of manufacture for use in programming a processing unit to transfer data between a first storage device and a second storage device, the article of manufacture comprising at least one computer readable storage device including at least one computer program embedded therein that causes the processing unit to perform:
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receiving a user specified cut-off time value in a command to ensure that data is consistent as of the user specified cut-off time;
obtaining information on data writes to the first storage device, including information on time stamp values associated with the data writes indicating an order of the data writes to the first storage device, wherein the steps of obtaining the information and forming groups of data writes are performed multiple times until the time stamp value is determined to be at or later in time than the user specified cut-off time value, forming at least one group of data writes having time stamp values earlier in time than the user specified cut-off time value;
transferring the data writes in the groups to the second storage device for storage therein; and
calculating a time stamp value by adding a predetermined time value to the time stamp value of a previously formed group of data writes after determining that there were no data writes to the first storage device since a previous instance of obtaining information. - View Dependent Claims (14, 15)
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Specification