Incremental data backup using a combined tracking data structure

A first computer node comprising:

• a memory;
• a hardware processor;
• and
• a non-transitory storage medium comprising instructions executable on the hardware processor to:
• maintain a first modified data tracking structure in the memory of the first computer node, wherein the first modified data tracking structure comprises indicators of modified data portions in a network-attached memory as modified by the first computer node;
• create a combined tracking data structure based on the first modified data tracking structure and a second modified data tracking structure maintained at a second computer node, the second modified data tracking structure comprising indicators of modified data portions in the network-attached memory as modified by the second computer node;
• store the combined tracking data structure in the network-attached memory;
• and
• initiate of an incremental data backup operation using the combined tracking data structure to copy modified data portions from the network-attached memory to a backup storage system.

A method of a system comprising a hardware processor, comprising:

• in a plurality of computer nodes, updating respective modified data tracking structures with modified indicators as data portions in a network-attached memory are modified with respect to a backup storage system;
• combining the modified data tracking structures into a combined tracking data structure;
• storing the combined tracking data structure at the network-attached memory;
• and
• as part of an incremental data backup operation, using the combined tracking data structure to back up the modified data portions from the network-attached memory to the backup storage system.