Method, system, and article of manufacture for data replication
First Claim
Patent Images
1. A method comprising:
- receiving an I/O command at a switch from a host;
if the I/O command is a write I/O, then writing data via the switch to a primary storage subsystem and a secondary storage subsystem, wherein the switch couples the host to the primary storage subsystem and the secondary storage subsystem, and wherein the data written to the primary storage subsystem and the data written to the secondary storage subsystem are the same;
receiving an indication of a failure of the primary storage subsystem at the switch; and
subsequently, directing a command from the host received at the switch to the secondary storage subsystem for completion by changing a source volume and a target volume in the command to correspond to volumes in the secondary storage subsystem, wherein the source volume and the target volume are for I/O operations, and wherein the changing is performed by a switching application in the switch, wherein a hardware unit is coupled to the primary storage subsystem, wherein the hardware unit traps alerts related to I/O failures and notifies the switch to perform the changing, and wherein in response to the hardware unit receiving a notification that the primary storage subsystem is fixed creating a copy of secondary storage subsystem data to guard against any subsequent failure during resynchronization of the primary and secondary storage systems.
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Abstract
Provided are a method, system and article of manufacture for switching. An indication is received of a failure of a primary storage subsystem at a switch, wherein the switch couples a host to the primary storage subsystem and a secondary storage subsystem. Subsequently, a command received from the host at the switch is directed to the secondary storage subsystem for completion.
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Citations
21 Claims
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1. A method comprising:
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receiving an I/O command at a switch from a host; if the I/O command is a write I/O, then writing data via the switch to a primary storage subsystem and a secondary storage subsystem, wherein the switch couples the host to the primary storage subsystem and the secondary storage subsystem, and wherein the data written to the primary storage subsystem and the data written to the secondary storage subsystem are the same; receiving an indication of a failure of the primary storage subsystem at the switch; and subsequently, directing a command from the host received at the switch to the secondary storage subsystem for completion by changing a source volume and a target volume in the command to correspond to volumes in the secondary storage subsystem, wherein the source volume and the target volume are for I/O operations, and wherein the changing is performed by a switching application in the switch, wherein a hardware unit is coupled to the primary storage subsystem, wherein the hardware unit traps alerts related to I/O failures and notifies the switch to perform the changing, and wherein in response to the hardware unit receiving a notification that the primary storage subsystem is fixed creating a copy of secondary storage subsystem data to guard against any subsequent failure during resynchronization of the primary and secondary storage systems. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A system comprising:
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a primary storage subsystem; a secondary subsystem; a switch, wherein the switch couples a host to the primary storage subsystem and the secondary storage subsystem; means for receiving an I/O command at a switch from a host; means for writing data via the switch to the primary storage subsystem and the secondary storage subsystem if the I/O command is a write I/O, and wherein the data written to the primary storage subsystem and the data written to the secondary storage subsystem are the same; means for receiving an indication of a failure of the primary storage subsystem at the switch; and means for directing a command from the host received at the switch to the secondary storage subsystem for completion, by changing a source volume and a target volume in the command to correspond to volumes in the secondary storage subsystem, wherein the source volume and the target volume are for I/O operations, and wherein the changing is performed by a switching application in the switch, wherein a hardware unit is coupled to the primary storage subsystem, wherein the hardware unit traps alerts related to I/O failures and notifies the switch to perform the changing, and wherein in response to the hardware unit receiving a notification that the primary storage subsystem is fixed creating a copy of secondary storage subsystem data to guard against any subsequent failure during resynchronization of the primary and secondary storage systems. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A computer readable storage medium including code, wherein the code in response to being executed by a processor is capable of causing operations, the operations comprising:
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receiving an I/O command at a switch from a host; if the I/O command is a write I/O, then writing data via the switch to a primary storage subsystem and a secondary storage subsystem, wherein the switch couples the host to the primary storage subsystem and the secondary storage subsystem, and wherein the data written to the primary storage subsystem and the data written to the secondary storage subsystem are the same; receiving an indication of a failure of the primary storage subsystem at the switch; and subsequently, directing a command from the host received at the switch to the secondary storage subsystem for completion by changing a source volume and a target volume in the command to correspond to volumes in the secondary storage subsystem, wherein the source volume and the target volume are for I/O operations, and wherein the changing is performed by a switching application in the switch, wherein a hardware unit is coupled to the primary storage subsystem, wherein the hardware unit traps alerts related to I/O failures and notifies the switch to perform the changing, and wherein in response to the hardware unit receiving a notification that the primary storage subsystem is fixed creating a copy of secondary storage subsystem data to guard against any subsequent failure during resynchronization of the primary and secondary storage systems. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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Specification