http://go7cnxivpns4x2trczyaabxwnrz7bwlxjiverkc32o4mjd5npjukpqid.onion/blog/2024-02-22-shrinking-xfs-partition-on-lvm.html
Here's the problem: raspberrypi3:~ # lvconvert --raidintegrity y icy_box/data
Volume group "icy_box" has insufficient free space (0 extents): 3832 required. It needs some space. And if your XFS has already been given all available space, you're stuck. You can't shrink XFS, right?