##I have a volumegroup called system , there are three physical volumes in it ,they are ##sda5,sda6,sda7; now i need to add a new physical volume called sda8 to volume group ##"system". And i should use command "pvmove" to move the data of sda5,sda6,sda7 to sda8.
##I have pvmoved the data of sda5 to sda8 now , and found that sda8 is full now . I can not ##move the data of sda6,sda7 to sda8 now . I don't know what shall i do .


root@apporc-ubuntu:~# pvdisplay /dev/sda5
  --- Physical volume ---
  PV Name               /dev/sda5
  VG Name               system
  PV Size               20.01 GiB / not usable 9.12 MiB
  Allocatable           yes
  PE Size               64.00 MiB
  Total PE              320
  Free PE               320
  Allocated PE          0
  PV UUID               c3I0OY-ypRR-Cmnb-GOi4-BL92-ctRP-jt8gUh

root@apporc-ubuntu:~# pvdisplay /dev/sda6
  --- Physical volume ---
  PV Name               /dev/sda6
  VG Name               system
  PV Size               20.01 GiB / not usable 9.12 MiB
  Allocatable           yes (but full)
  PE Size               64.00 MiB
  Total PE              320
  Free PE               0
  Allocated PE          320
  PV UUID               IK7zPs-InfU-BhyA-thjV-DAL1-VsaK-elDeeA

root@apporc-ubuntu:~# pvdisplay /dev/sda7
  --- Physical volume ---
  PV Name               /dev/sda7
  VG Name               system
  PV Size               20.01 GiB / not usable 9.12 MiB
  Allocatable           yes
  PE Size               64.00 MiB
  Total PE              320
  Free PE               48
  Allocated PE          272
  PV UUID               AdfbZU-NwUx-dcbo-Oxzk-zdHY-lSHG-notTfN

root@apporc-ubuntu:~# pvdisplay /dev/sda8
  --- Physical volume ---
  PV Name               /dev/sda8
  VG Name               system
  PV Size               20.01 GiB / not usable 9.12 MiB
  Allocatable           yes
  PE Size               64.00 MiB
  Total PE              320
  Free PE               48
  Allocated PE          272
  PV UUID               7NXoFq-SQBI-IVER-ZhAK-wRzX-ODqp-RD2VDc

  --- Volume group ---
  VG Name               system
  System ID
  Format                lvm2
  Metadata Areas        4
  Metadata Sequence No  36
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                10
  Open LV               6
  Max PV                0
  Cur PV                4
  Act PV                4
  VG Size               80.00 GiB
  PE Size               64.00 MiB
  Total PE              1280
  Alloc PE / Size       864 / 54.00 GiB
  Free  PE / Size       416 / 26.00 GiB
  VG UUID               TBf1nJ-x7Ln-o84N-YRYy-yNW7-A8bh-7CjG6M