root@host # pvs -v --segments /dev/sda1
PV         VG      Fmt  Attr PSize PFree   Start SSize LV      Start PE
/dev/sda1  vg_arch lvm2 a--    XXX   XXX       0   128 lv_root     0 linear /dev/sda1:0-127
/dev/sda1  vg_arch lvm2 a--    XXX   XXX     128     1             0 free
/dev/sda1  vg_arch lvm2 a--    XXX   XXX     129   128 lv_root   128 linear /dev/sda1:129-256

PV         VG      Fmt  Attr PSize PFree   Start SSize LV      Start PE
/dev/sda1  vg_arch lvm2 a--    XXX   XXX       0   256 lv_root     0 linear /dev/sda1:0-255
/dev/sda1  vg_arch lvm2 a--    XXX   XXX     256     1             0 free

# pvmove --alloc anywhere /dev/sda1:129 /dev/sda1:128
# pvmove --alloc anywhere /dev/sda1:130 /dev/sda1:129
# pvmove --alloc anywhere /dev/sda1:131 /dev/sda1:130
  ...
# pvmove --alloc anywhere /dev/sda1:256 /dev/sda1:255