Check whether the disk space on the server of the source database is sufficient. During migration of a self-built source instance, at least 50 GB disk space should be reserved on the server of the source database. We recommend you reserve a space at least 1.5 times the size of the migration data to avoid errors; otherwise, an error will be reported with the error details: "Check whether the disk space on the destination server is sufficient.".
Fixing Method
If a disk space check error is reported: "Check whether the disk space on the destination server is sufficient," please check the purchased disk space size of the target instance. It is recommended that the disk space of the target instance is not smaller than the disk space of the source instance, preferably 1.5 times the size of the source instance's disk space. You can expand the disk space size of the target instance through the Adjusting Instance Specification feature in the console.