What happens if you stop this process?

Question

linux

Started defragmentation with the xfs_fsr -v /dev/sdb1 command. 2TB external hard drive, 400 GB occupied on it. What happens if you stop the process and how long will it take?
https://drive.google.com/file/d/1Gp9mEH6YvmOQj_EcP...
photo

Answer 1

Nothing will happen.
Defragmentation is the operation of moving file extents (physical allocation blocks) so that they eventually merge, preferably into one. This usually requires at least two copy operations, one to move the blocks to free working space on disk so that more can be moved, and the other to finally move the blocks to their intended location. In this paradigm, data is never deleted from the disk, so the operation can be safely stopped even if the power goes out.
Source