Regenerating a chain of backups
AssigneeDell Products L.P.
InventorsSunil Yadav, Shelesh Chopra
Life of this patent
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Abstract
A synthetic full backup of a source volume is retrieved, the synthetic full having been created from merging a backup chain including an incremental backup into a full backup. The full backup corresponds to a state of the source volume at a first time. The synthetic full corresponds to a state of the source volume at a second time, after the first time. A bitmap embedded into a snapshot of the source volume taken at the second time is retrieved. The bitmap identifies data from the source volume copied to secondary storage for the incremental backup. The backup chain is regenerated by copying from the snapshot the data identified by the bitmap to a regenerated incremental backup.
Claims19
A method comprising:
- creating, by a processor, a full backup image of a source volume, the full backup image corresponding to a state of the source volume at a first time;
- tracking, in a first bitmap, changes to the source volume since the first time;
- taking a first snapshot of the source volume at a second time, after the first time;
- embedding the first bitmap into the first snapshot;
- creating a first incremental backup image of the source volume by backing up the changes from the first snapshot according to the first bitmap;
- merging a backup chain comprising the first incremental backup image and the full backup image to create a first synthetic full backup image, the first synthetic full backup image thereby corresponding to a state of the source volume at the second time, the state of the source volume at the first time now being lost because the full backup image has been merged with the first incremental backup image;
- after the merge, retrieving the first bitmap embedded into the first snapshot of the source volume taken at the second time;
- examining the first bitmap to identify the changes made to the source volume since the first time;
- and
- based on the changes according to the first bitmap, regenerating the backup chain to obtain the full backup image and thereby the state of the source volume at the first time and not the second time.
A system for backup chain regeneration comprising:
- a processor;
- and memory configured to store one or more sequences of instructions which, when executed by the processor, cause the processor to carry out the steps of:
- creating a full backup image of a source volume, the full backup image corresponding to a state of the source volume at a first time;
- tracking, in a first bitmap, changes to the source volume since the first time;
- taking a first snapshot of the source volume at a second time, after the first time;
- embedding the first bitmap into the first snapshot;
- creating a first incremental backup image of the source volume by backing up the changes from the first snapshot according to the first bitmap;
- merging a backup chain comprising the first incremental backup image and the full backup image to create a first synthetic full backup image, the first synthetic full backup image thereby corresponding to a state of the source volume at the second time, the state of the source volume at the first time now being lost because the full backup image has been merged with the first incremental backup image;
- after the merge, retrieving the first bitmap embedded into the first snapshot of the source volume taken at the second time;
- examining the first bitmap to identify the changes made to the source volume since the first time;
- and
- based on the changes according to the first bitmap, regenerating the backup chain to obtain the full backup image and thereby the state of the source volume at the first time and not the second time.
A computer program product, comprising a non-transitory computer-readable medium having a computer-readable program code embodied therein, the computer-readable program code adapted to be executed by one or more processors to implement a method for backup chain regeneration comprising:
- creating a full backup image of a source volume, the full backup image corresponding to a state of the source volume at a first time;
- tracking, in a first bitmap, changes to the source volume since the first time;
- taking a first snapshot of the source volume at a second time, after the first time;
- embedding the first bitmap into the first snapshot;
- creating a first incremental backup image of the source volume by backing up the changes from the first snapshot according to the first bitmap;
- merging a backup chain comprising the first incremental backup image and the full backup image to create a first synthetic full backup image, the first synthetic full backup image thereby corresponding to a state of the source volume at the second time, the state of the source volume at the first time now being lost because the full backup image has been merged with the first incremental backup image;
- after the merge, retrieving the first bitmap embedded into the first snapshot of the source volume taken at the second time;
- examining the first bitmap to identify the changes made to the source volume since the first time;
- and
- based on the changes according to the first bitmap, regenerating the backup chain to obtain the full backup image and thereby the state of the source volume at the first time and not the second time.
Dependencies are inferred from the claim text.