US 7,743,028 B1Granted

Incremental backup of partial volumes

AssigneeSymantec Corporation

InventorsRussell Stringham, Paul Madden, Jonathan Ludwig

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Abstract

Mechanisms for generating an incremental backup of a set of data blocks while excluding certain files that are less desired to be backed up. Examples of such files include temporary Internet files and the recycle bin. This allows the size of the incremental backup to be reduced significantly since such undesired files are often changed between backups. The incremental backup is constructed by first calculating which data blocks should be included in the incremental backup. The calculation is a function of at least the identity of which if any of the data blocks in a prior snapshot have been or would have been altered as a result of potential file alterations in the prior snapshot, and/or which if any of the data blocks in the subsequent snapshot have been or would have been altered as a result of potential file alterations in the subsequent snapshot.

Claims22

Dependent claims

A method for generating an incremental backup of a set of data blocks, the method comprising:

taking a first snapshot of the set of data blocks;
altering the first snapshot by deleting one or more files stored in a temporary storage location from the first snapshot, wherein the deleted files are associated with data blocks included in the first snapshot, and wherein the temporary storage location comprises a volume on a hard disk drive;
wherein deleting one or more files associated with a first data block comprises:
modifying a pointer in a second data block configured to point to the one or more files associated with the first data block, wherein the modified pointer is configured to not point to the one or more files associated with the first data block;
and
deallocating memory associated with the first data block;
identifying which data blocks in the first snapshot have been altered as a result of deleting the one or more files from the first snapshot;
performing a first backup of the set of data blocks using at least a portion of the first snapshot;
taking a second snapshot of the set of data blocks subsequent to taking a first snapshot of the set of data blocks;
identifying which data blocks of the set of data blocks have changed between the first and second snapshots;
and
calculating which of the set of data blocks in the second snapshot to back up in a second backup of the set of data blocks, wherein the second backup is an incremental backup and wherein the calculation is a function of at least the identity of which data blocks in the first snapshot have been altered during the deleting of the one or more files from the first snapshot, and wherein calculating which of the set of data blocks in the second snapshot to back up in the second backup is also a function of at least the identity of which data blocks of the set of data blocks have changed between the first and second snapshots.

9 more elements

A computer-readable storage medium having computer-readable instructions, the computer-readable instructions being executable by a computer processor to:

take a first snapshot of a set of data blocks;
alter the first snapshot by deleting one or more files stored in a temporary storage location from the first snapshot, wherein the deleted files are associated with data blocks included in the first snapshot, and wherein the temporary storage location comprises a volume on a hard disk drive;
wherein the computer-readable instructions to alter the first snapshot by deleting one or more files associated with a first data block are executable by a computer processor to:
modify a pointer in a second data block configured to point to the one or more files associated with the first data block, wherein the modified pointer is configured to not point to the one or more files associated with the first data block;
and
deallocate memory associated with the first data block;
identify which data blocks in the first snapshot have been altered as a result of the deletion of the one or more files from the first snapshot;
perform a first backup of the set of data blocks using at least a portion of the first snapshot;
take a second snapshot of the set of data blocks subsequent to the first snapshot of the set of data blocks;
identify which data blocks of the set of data blocks have changed between the first and second snapshots;
and
calculate which of the set of data blocks in the second snapshot to back up in a second backup of the set of data blocks, wherein the second backup is an incremental backup and wherein the calculation is a function of at least the identity of which data blocks in the first snapshot have been altered during the deletion of the one or more files from the first snapshot, and wherein the calculation of which of the set of data blocks in the second snapshot to back up in the second backup is also a function of at least the identity of which data blocks of the set of data blocks have changed between the first and second snapshots.

9 more elements

A method for generating an incremental backup of a set of data blocks, the method comprising:

taking a current snapshot of the set of data blocks;
altering the current snapshot by deleting one or more files stored in a temporary storage location from the current snapshot, wherein the deleted files are associated with data blocks included in the current snapshot, and wherein the temporary storage location comprises a volume on a hard disk drive;
wherein deleting one or more files associated with a first data block comprises:
modifying a pointer in a second data block configured to point to the one or more files associated with the first data block, wherein the modified pointer is configured to not point to the one or more files associated with the first data block;
and
deallocating memory associated with the first data block;
identifying which data blocks in the current snapshot have been altered as a result of deleting the one or more files from the current snapshot;
identifying which data blocks of the set of data blocks have changed between the current snapshot and a prior snapshot;
and
calculating which of the set of data blocks in the current snapshot of the set of data blocks to incrementally back up in a current backup as a function of at least the identity of which data blocks in the current snapshot have been altered during the deleting of one or more files from the current snapshot, and wherein calculating which of the set of data blocks in the current snapshot to incrementally back up is also a function of at least the identity of which data blocks of the set of data blocks have changed between the prior and current snapshots.

7 more elements

A computer-readable storage medium having computer-readable instructions, the computer-readable instructions being executable by a computer processor to:

take a first snapshot of a set of data blocks;
alter the first snapshot by deleting one or more files stored in a temporary storage location from the first snapshot, wherein the deleted files are associated with data blocks included in the first snapshot, and wherein the temporary storage location comprises a volume on a hard disk drive;
wherein the computer-readable instructions to alter the first snapshot by deleting one or more files associated with a first data block are executable by a computer processor to:
modify a pointer in a second data block configured to point to the one or more files associated with the first data block, wherein the modified pointer is configured to not point to the one or more files associated with the first data block;
and
deallocate memory associated with the first data block;
identify which data blocks in the first snapshot have been altered as a result of deleting the one or more files from the first snapshot;
perform a first backup of the set of data blocks using at least a portion of the first snapshot;
take a second snapshot of the set of data blocks subsequent to the first snapshot of the set of data blocks;
identify which data blocks of the set of data blocks have changed between the first and second snapshots;
and
calculate which of the set of data blocks in the second snapshot to back up in a second backup of the set of data blocks, wherein the second backup is an incremental backup and wherein the calculation is a function of at least the identity of which data blocks in the first snapshot have been altered during the deletion of the one or more files from the first snapshot, and wherein the calculation of which of the set of data blocks in the second snapshot to back up in the second backup is also a function of at least the identity of which data blocks of the set of data blocks have changed between the first and second snapshots.

9 more elements

A computer-readable storage medium having computer-readable instructions, the computer-readable instructions being executable by a computer processor to:

take a current snapshot of a set of data blocks;
alter the current snapshot by deleting one or more files stored in a temporary storage location from the current snapshot, the deleted files are associated with data blocks included in the current snapshot, wherein the temporary storage location comprises a volume on a hard disk drive;
wherein the computer-readable instructions to alter the current snapshot by deleting one or more files associated with a first data block are executable by a computer processor to:
modify a pointer in a second data block configured to point to the one or more files associated with the first data block, wherein the modified pointer is configured to not point to the one or more files associated with the first data block;
and
deallocate memory associated with the first data block;
identify which data blocks in the current snapshot have been altered as a result of the deletion of the one or more files from the first snapshot;
identify which data blocks of the set of data blocks have changed between the current snapshot and a prior snapshot;
and
calculate which of the set of data blocks in the current snapshot of the set of data blocks to incrementally back up in a current backup as a function of at least the identity of which data blocks in the current snapshot have been altered during the deletion of the one or more files from the first snapshot, and wherein the calculation of which of the set of data blocks in the current snapshot to incrementally back up is also a function of at least the identity of which data blocks of the set of data blocks have changed between the prior and current snapshots.

7 more elements

Dependencies are inferred from the claim text.