Data set autorecovery
First Claim
1. A computer program product stored on a non-transitory computer-readable storage medium comprising instructions for:
- receiving, on a first system, an error condition indicating that a virtual storage access method (VSAM) volume data set (VVDS) on a volume shared by the first system and one or more second systems is not found;
locking the volume from receiving changes in response to the error condition;
sending a request to one or more of the second systems in response to receiving the error condition, the request requesting VVDS location information from a second system that has the VVDS open in a memory of the second system, the VVDS location information comprising control blocks, the control blocks storing extent information for the VVDS, wherein only systems with the VVDS open comprise the control blocks; and
recovering the VVDS using the VVDS location information retrieved by the second system that has the VVDS open by copying the extent information from the control blocks in the memory of the second system to a new VVDS entry in a volume table of content (VTOC).
1 Assignment
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Accused Products
Abstract
An approach to providing auto recovery of data sets in volumes. When an error condition results from an attempt to access an unintentionally deleted data set, an event is generated and sent to other systems with access to the volume in which the data set existed. The volume is also locked to prevent corruption during the recovery process. A system that has the unintentionally deleted data set open retrieves location information for the data set from control blocks in the system'"'"'s memory. This location information is used to build a new entry for the data set in the VTOC for the volume. When the data set is thus recovered, the data set is validated, the lock removed, and the data set is made available to the systems sharing the volume.
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Citations
17 Claims
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1. A computer program product stored on a non-transitory computer-readable storage medium comprising instructions for:
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receiving, on a first system, an error condition indicating that a virtual storage access method (VSAM) volume data set (VVDS) on a volume shared by the first system and one or more second systems is not found; locking the volume from receiving changes in response to the error condition; sending a request to one or more of the second systems in response to receiving the error condition, the request requesting VVDS location information from a second system that has the VVDS open in a memory of the second system, the VVDS location information comprising control blocks, the control blocks storing extent information for the VVDS, wherein only systems with the VVDS open comprise the control blocks; and recovering the VVDS using the VVDS location information retrieved by the second system that has the VVDS open by copying the extent information from the control blocks in the memory of the second system to a new VVDS entry in a volume table of content (VTOC). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system comprising:
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a virtual storage access method (VSAM) volume having one or more VSAM volume data sets (VVDS); a first system having access to the volume; one or more second systems having access to the volume; and a data set auto-recovery apparatus configured to; receive an error condition from the first system indicating that a VVDS on the volume is not found; lock the volume from receiving changes in response to the error condition; send an request to the one or more second systems in response to receiving the error condition, the request requesting location information from a second system that has the VVDS open in a memory of the second system, the VVDS location information comprising control blocks, the control blocks storing extent information for the VVDS, wherein only systems with the VVDS open comprise the control blocks; and recover the VVDS using the location information retrieved by the second system that has the VVDS open by copying the extent information from the control blocks in the memory of the second system to a new VVDS entry in a volume table of content (VTOC). - View Dependent Claims (10, 11, 12, 13)
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14. A method comprising:
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receiving, on a first system, an error condition indicating that a virtual storage access method (VSAM) volume data set VVDS on a VSAM volume shared by the first system and one or more second systems is not found; locking the volume from receiving changes in response to the error condition; sending an request to one or more of the second systems in response to receiving the error condition, the request requesting location information for the VVDS from a second system that has the VVDS open in a memory of the second system, the VVDS location information comprising control blocks, the control blocks storing extent information for the VVDS, wherein only systems with the VVDS open comprise the control blocks; and recovering the VVDS using the location information retrieved by the second system that has the data set open by copying the extent information from the control blocks in the memory of the second system to a new VVDS entry in a volume table of content (VTOC). - View Dependent Claims (15, 16, 17)
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Specification