Data set level mirroring to accomplish a volume merge/migrate in a digital data storage system
First Claim
1. A method for combining extents of a source data set, with minimal down time imposed on applications accessing the source data set, the source data set having a corresponding name, source DASD device(s) and one or more extent locations on the source DASD device(s), the method comprising the steps of:
- a) assessing the source data set to be migrated, the volume(s) it resides on, and the total space it occupies;
b) allocating space for a corresponding target data set using the total source space as a primary allocation request and using the original source data set name;
c) designating one or more target locations in the allocated space and assigning each source data set extent location to a respective one or more of the designated target locations;
d) starting monitor programs on any images that can write to any of the identified source volumes in order to detect a subsequent change to the source data set;
e) storing an indication of each source data set track detected by a monitor program as having changed;
f) begin copying the source data set in accordance with said assignment of each source data set extent so as to form the corresponding target data set;
g) while copying the source data set, periodically re-synchronizing source and target tracks detected by the monitor programs as having changed after having been previously copied;
h) upon substantial completion of said copying, signaling the said application programs that closing the source data set is requested;
i) recognizing that the source data set is closed thereby commencing a down time window;
j) during the downtime window, finally re-synchronizing the source and target tracks detected by the monitor programs as having changed after having been previously copied;
k) during the downtime window, accommodating allocation differences that occurred since the initial assessment of the source data set;
l) changing catalog entries to reflect new target data set volumes; and
m) signaling the application(s) that the target data set may be opened, thereby terminating the down time window.
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Accused Products
Abstract
Users of Mainframe computers running under IBM'"'"'s MVS operating systems have a need to merge migrate data from multiple smaller DASD devices (disk volumes) to larger DASD devices, and/or to migrate data in order to combine data set extents. A method is disclosed for migrating data where a volume merge is involved, and/or when combining of extents is desired, that minimizes the down time of applications using the involved data while satisfying MVS rules for volume and catalog meta-data files as well as data extent limitations. The method may be implemented such that source and target volumes need not be in like manufacturer DASD devices.
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Citations
6 Claims
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1. A method for combining extents of a source data set, with minimal down time imposed on applications accessing the source data set, the source data set having a corresponding name, source DASD device(s) and one or more extent locations on the source DASD device(s), the method comprising the steps of:
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a) assessing the source data set to be migrated, the volume(s) it resides on, and the total space it occupies;
b) allocating space for a corresponding target data set using the total source space as a primary allocation request and using the original source data set name;
c) designating one or more target locations in the allocated space and assigning each source data set extent location to a respective one or more of the designated target locations;
d) starting monitor programs on any images that can write to any of the identified source volumes in order to detect a subsequent change to the source data set;
e) storing an indication of each source data set track detected by a monitor program as having changed;
f) begin copying the source data set in accordance with said assignment of each source data set extent so as to form the corresponding target data set;
g) while copying the source data set, periodically re-synchronizing source and target tracks detected by the monitor programs as having changed after having been previously copied;
h) upon substantial completion of said copying, signaling the said application programs that closing the source data set is requested;
i) recognizing that the source data set is closed thereby commencing a down time window;
j) during the downtime window, finally re-synchronizing the source and target tracks detected by the monitor programs as having changed after having been previously copied;
k) during the downtime window, accommodating allocation differences that occurred since the initial assessment of the source data set;
l) changing catalog entries to reflect new target data set volumes; and
m) signaling the application(s) that the target data set may be opened, thereby terminating the down time window. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification