Methods for generating a synthetic backup and for consolidating a chain of backups independent of endianness

Patent metadata

Field	Value
Publication number	US-9703644-B1
Application number	US-201414564971-A
Country	US
Kind code	B1
Filing date	Dec 9, 2014
Priority date	Dec 9, 2014
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

Systems and methods for generating synthetic backups and for consolidating a chain of related backups. The chain of related backups is merged on the fly to create a backup stream. A block allocation table (BAT) may be identified for each backup to be consolidated into a synthetic backup, and BAT entries from each backup may be merged or combined to create a new BAT table associated with the synthetic backup. The data included in the related backups may be reformatted on the fly from big endian to little endian or vice versa. The backup stream is stored on a target device or volume.

First claim

What is claimed is:

1. A method for generating a synthetic backup from a chain of related backups, the method comprising:
merging BAT (Block Allocation Table) entries from each backup in the chain of related backups into a new BAT associated with the synthetic backup;
determining payload blocks from the chain of related backups to be merged from the new BAT;
generating a backup stream that is stored as the synthetic backup in a target volume; and
while generating the backup stream, merging the payload blocks in accordance with index data included in corresponding block entries from the new BAT, wherein a format of the payload blocks is changed from a first format to a second format associated with the target volume.

2. The method of claim 1 , wherein the first format is big endian and the second format is little endian or wherein the first format is little endian and the second format is big endian.

3. The method of claim 1 , wherein the backup stream is a Hyper-V Virtual Hard Drive (VHDx) stream.

4. The method of claim 1 , wherein the format is changed from the first format to the second format on the fly.

5. The method of claim 1 , wherein the change from the first format to the second format is independent of a format associated with an operating system of a machine on which the chain of related backups is stored.

6. The method of claim 1 , wherein entries in the new BAT include an index array, wherein each index in the index array identifies a start, a length, and an id that identifies one of the backups in the chain of backups.

7. A method for consolidating a chain of related backups that include a full backup and one or more incremental backups, the method comprising:
identifying a Block Allocation Table (BAT) for each backup in the chain of related backups to be consolidated into a synthetic backup;
combining entries in the BATs to create a new BAT, wherein the new BAT identifies data from the chain of related backups that is to be merged;
looping through the entries in the new BAT, wherein each entry is associated with a backup block and wherein data identified in the entries is merged while creating a backup stream that includes the new BAT and the merged data; and
streaming the backup stream to a target.

8. The method of claim 7 , further comprising changing entries in the BATs associated with a first format such that the BAT entries are associated with a second format.

9. The method of claim 8 wherein the BAT entries are converted based on their endianness.

10. The method of claim 8 , further comprising changing data in the first format to the second format.

11. The method of claim 7 , wherein non-zero entries in the new BAT are filled with zeros.

12. The method of claim 7 , further comprising reading data from each block of the backups identified in the new BAT and writing the read data to the target.

13. The method of claim 12 , wherein the target is a virtual target that can be mounted as a virtual disk.

14. The method of claim 7 , wherein an image of the backup can be recovered on any machine regardless of an endianness of the machine.

Assignees

• Emc Corp
• Emc Ip Holding Co Llc

Inventors

• Jagannatha Manjunath
• Varadaraju Kiran Kumar Madiraju
• Ati Pavan Kumar Dattatreya

Classifications

• G06F11/1448

  Management of the data involved in backup or backup restore · CPC title

• G06F11/1435

  using file system or storage system metadata · CPC title

• G06F11/1469

  Backup restoration techniques · CPC title

• G06F11/1464 Primary

  for networked environments · CPC title

• G06F11/1451

  by selection of backup contents · CPC title