LAN-free and application consistent backup method

A method for a storage system connected to a backup storage system over a Storage Area Network (SAN), the backup storage system being managed by a backup server, the storage system comprising a primary volume and a secondary volume configured to be mapped from a backup volume in the backup storage system and configured to be paired with the primary volume, the method comprising:

• for receipt of a backup operation request from the backup server:
• copying the primary volume to the secondary volume through a pair operation based on an Input/Output (I/O) between the storage system and a host computer managing the storage system;
• mapping the backup volume to the secondary volume;
• and
• based on the I/O, copying the secondary volume to the backup volume through the SAN,
• wherein the copying the primary volume to the secondary volume through the pair operation based on the I/O between the storage system and the host computer managing the storage system comprises:
• providing a first difference bitmap and a second difference bitmap between the primary volume and the secondary volume, the first difference bitmap indicative of differences in logical block addresses LBAs between the primary volume and the secondary volume to be copied over for the backup operation, the second difference bitmap indicative of current differences in LBAs between the primary volume and the secondary volume;
• for each LBA in the first difference bitmap indicative of a difference:
• copying the each LBA from the primary volume to the secondary volume;
• and
• upon completion of the copying of the eachLBA, setting the first difference bitmap corresponding to the each LBA as not having a difference, and
• wherein the providing the first difference bitmap and the second difference bitmap between the primary volume and the secondary volume comprises copying the first difference bitmap to the second difference bitmap in response to the backup operation request.

A non-transitory computer readable medium, storing instructions for a storage system connected to a backup storage system over a Storage Area Network (SAN), the backup storage system being managed by a backup server, the storage system comprising a primary volume and a secondary volume configured to be mounted to a backup volume in the backup storage system and configured to be paired with the primary volume, the instructions comprising:

• for receipt of a backup operation request from the backup server:
• copying the primary volume to the secondary volume through a pair operation based on an Input/Output (I/O) between the storage system and a host computer managing the storage system;
• mapping the backup volume to the secondary volume;
• and
• based on the I/O, copying the secondary volume to the backup volume through the SAN,
• wherein the copying the primary volume to the secondary volume through the pair operation based on the I/O between the storage system and the host computer managing the storage system comprises:
• providing a first difference bitmap and a second difference bitmap between the primary volume and the secondary volume, the first difference bitmap indicative of differences in logical block addresses LBAs between the primary volume and the secondary volume to be copied over for the backup operation, the second difference bitmap indicative of current differences in LBAs between the primary volume and the secondary volume;
• for each LBA in the first difference bitmap indicative of a difference:
• copying the each LBA from the primary volume to the secondary volume;
• and
• upon completion of the copying of the each LBA, setting the first difference bitmap corresponding to the each LBA as not having a difference, and
• wherein the providing the first difference bitmap and the second difference bitmap between the primary volume and the secondary volume comprises copying the first difference bitmap to the second difference bitmap in response to the backup operation request.