Multi-environment data consistency

Claim 7

The method of claim 3 , wherein the predetermined time value represents a time interval between instances of obtaining information on data writes.

Claim 8

The method of claim 3 , wherein data transfers to volumes in the second storage device are suspended after determining that the calculated time is later in time than the cut-off time value.

Claim 11

The system of claim 6 , wherein the memory area is included within the second storage device.

Claim 12

The system of claim 6 , wherein the host system is in a first location, wherein the first processing unit and first storage device are in a second location, wherein the second storage device is in a third location, wherein the first, second, and third locations are in separate geographical locations, further including: 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.

Claim 17

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: 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.

Claim 18

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: 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.

Claim 19

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: 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.

Claim 20

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: 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.

Claim 21

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: 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.

Claim 22

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: 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.

Claim 23

The article of manufacture of claim 13 , wherein the predetermined time value represents a time interval between instances of obtaining information on data writes.

Claim 24

The article of manufacture of claim 13 , wherein data transfers to volumes in the second storage device are suspended after determining that the calculated time is later in time than the cut-off time value.