Container data mover for migrating data between distributed data storage systems integrated with application orchestrators

A first cloud computing environment hosting a first distributed data storage system for out-migrating data therefrom, wherein the first distributed data storage system comprises:

• a first storage service node configured in the first cloud computing environment;
• a second storage service node, which is configured in the first cloud computing environment and comprises metadata associated with a first virtual disk, wherein the first virtual disk is configured as a persistent volume in a framework of an application orchestrator hosted by the first cloud computing environment;
• third storage service nodes, which are configured in the first cloud computing environment and comprise payload data of the first virtual disk, wherein one or more containerized applications of the application orchestrator generate the payload data;
• and
• wherein the second storage service node is configured to:
• take a first snapshot of at least part of the metadata associated with the first virtual disk, wherein a custom resource definition within the framework of the application orchestrator defines a schedule-and-retention policy applicable to the first snapshot;
• on taking the first snapshot, cause the first storage service node to increment a generation counter from a first value to a second value;
• based on determining that the first virtual disk is migration-enabled, identify at the third storage service nodes a first set of payload data files that are associated with the first value of the generation counter;
• migrate the first set of payload data files associated with the first value of the generation counter to a second virtual disk at a second distributed data storage system, which is distinct from the first distributed data storage system, wherein the second virtual disk is configured to correspond to the first virtual disk, comprising:
• (i) cause the third storage service nodes comprising the one or more payload data files of the first set to transmit, via kernel-to-kernel copy operations, respective payload data files to corresponding storage service nodes at a second distributed data storage system, which is distinct from the first distributed data storage system, and
• (ii) based on receiving permission from the first storage service node, transmit metadata captured in the first snapshot to a storage service node at the second distributed data storage system using metadata-write operations, which are distinct from and exclusive of the kernel-to-kernel write operations.