Upgrading the file system of objects in a distributed storage system

A non-transitory computer readable medium comprising instructions to be executed in a computing device to cause the computing device to carry out a method of upgrading a distributed storage object from a first version to a second version, comprising:

• querying metadata of a first component, the first component configured according to the first version of the distributed storage object, the metadata defining extents of data on a disk group of the first component;
• populating, for a second component configured according to the second version of the distributed storage object, a logical map and a middle map based on the metadata, initial entries in the logical map point to initial entries in the middle map, and the initial entries in the middle map point to physical addresses of the disk group of the first component;
• and
• reading the data from the disk group of the first component and writing the data to a disk group of the second component while updating the initial entries in the middle map.

A virtualized computing system having a cluster comprising hosts connected to a network, the virtualized computing system comprising:

• hardware platforms of the hosts configured to execute software platforms including distributed storage software;
• shared storage comprising local storage devices of the hardware platforms, the shared storage storing a distributed storage object managed by the distributed storage software;
• an upgrade manager of the distributed storage software configured to upgrade the distributed storage object from a first version to a second version by:
• querying metadata of a first component, the first component configured according to the first version of the distributed storage object, the metadata defining extents of data on a disk group of the first component;
• populating, for a second component configured according to the second version of the distributed storage object, a logical map and a middle map based on the metadata, initial entries in the logical map point to initial entries in the middle map, and the initial entries in the middle map point to physical addresses of the disk group of the first component;
• and
• reading the data from the disk group of the first component and writing the data to a disk group of the second component while updating the initial entries in the middle map.