Systems and methods for performing a fast resynchronization of a mirrored aggregate of a distributed storage system using disk-level cloning are provided. According to one embodiment, responsive to a failure of a disk of a plex of the mirrored aggregate utilized by a high-availability (HA) pair of nodes of a distributed storage system, disk-level clones of the disks of a healthy plex may be created external to the distributed storage system and attached to the degraded HA partner node. After detection of the cloned disks by the degraded HA partner node, mirror protection may be efficiently re-established by assimilating the cloned disks within the failed plex and then resynchronizing the mirrored aggregate by performing a level-1 resync of the failed plex with the healthy plex based on a base file system snapshot of the healthy plex. In this manner, a more time-consuming level-0 resync may be avoided.