As you can see below, that /dev/hdb7 acquires all the PE's (which in this case is the whole operating system). Each other physical volumes physical extents that are free (none are used) equals to the total of pe's used in /dev/hdb7 30515 - 21043 = 9472.

I am using pvmove -v --alloc anywhere /dev/hdb7 to move all the physical extents off /dev/hdb7 to the other physical volumes. That being said, it just leaves this hanging

 --- Physical volumes ---
  PV Name               /dev/hdb1
  PV UUID               DpcxQi-9qHf-pITK-deQ2-zbW7-8ywG-rGp7W6
  PV Status             allocatable
  Total PE / Free PE    2386 / 2386

  PV Name               /dev/hdb2
  PV UUID               keQJS3-rbDe-kXZf-n17o-EZ5n-2Bs8-CKrPYr
  PV Status             allocatable
  Total PE / Free PE    1194 / 1194

  PV Name               /dev/hdb3
  PV UUID               x6Vl7h-yhFr-fSE6-eaqK-EUvX-Bvcp-uOix7r
  PV Status             allocatable
  Total PE / Free PE    1194 / 1194

  PV Name               /dev/hdb5
  PV UUID               rbHmg7-3AXC-nH4V-hfO2-mzG9-7E73-m50ndq
  PV Status             allocatable
  Total PE / Free PE    2386 / 2386

  PV Name               /dev/hdb6
  PV UUID               IZAIeb-prQl-g3Ff-qoDD-sQti-t8di-AnoVCi
  PV Status             allocatable
  Total PE / Free PE    478 / 478

  PV Name               /dev/hdb7
  PV UUID               QWybhr-RRBj-0Xks-LZqp-c7oC-MfC0-DZvDXH
  PV Status             allocatable
  Total PE / Free PE    30515 / 21043

  PV Name               /dev/hda9
  PV UUID               bDkGUr-0rL8-srcF-RhIg-xrw2-byjS-CKDRkJ
  PV Status             allocatable
  Total PE / Free PE    2433 / 2433



tuxie var # pvmove -v --alloc anywhere /dev/hdb7
    Wiping cache of LVM-capable devices
    Finding volume group "myvg"
    Archiving volume group "myvg" metadata (seqno 33).
    Creating logical volume pvmove0
    Moving 2560 extents of logical volume myvg/usr
    Moving 2560 extents of logical volume myvg/home
    Moving 1280 extents of logical volume myvg/opt
    Moving 2560 extents of logical volume myvg/var
    Moving 512 extents of logical volume myvg/tmp
    Found volume group "myvg"
    Found volume group "myvg"
    Found volume group "myvg"
    Found volume group "myvg"
    Found volume group "myvg"
    Updating volume group metadata
    Creating volume group backup "/etc/lvm/backup/myvg" (seqno 34).
    Found volume group "myvg"
    Found volume group "myvg"
    Suspending myvg-usr (254:0)
    Found volume group "myvg"
    Found volume group "myvg"
    Suspending myvg-home (254:1)
    Found volume group "myvg"
    Found volume group "myvg"
    Suspending myvg-opt (254:2)
    Found volume group "myvg"
    Found volume group "myvg"
    Suspending myvg-var (254:3)
    Found volume group "myvg"
    Found volume group "myvg"
    Suspending myvg-tmp (254:4)
    Found volume group "myvg"
    Creating myvg-pvmove0
    Loading myvg-pvmove0 table
    Resuming myvg-pvmove0 (254:5)
    Found volume group "myvg"
    Loading myvg-pvmove0 table
    Suppressed myvg-pvmove0 identical table reload.
    Loading myvg-usr table
    Resuming myvg-usr (254:0)
    Found volume group "myvg"
    Loading myvg-pvmove0 table
    Suppressed myvg-pvmove0 identical table reload.
    Loading myvg-home table
    Resuming myvg-home (254:1)
    Found volume group "myvg"
    Loading myvg-pvmove0 table
    Suppressed myvg-pvmove0 identical table reload.
    Loading myvg-opt table
    Resuming myvg-opt (254:2)
    Found volume group "myvg"
    Loading myvg-pvmove0 table
    Suppressed myvg-pvmove0 identical table reload.
    Loading myvg-var table
    Resuming myvg-var (254:3)
    Found volume group "myvg"
    Loading myvg-pvmove0 table
    Suppressed myvg-pvmove0 identical table reload.
    Loading myvg-tmp table
    Resuming myvg-tmp (254:4)
    Checking progress every 15 seconds
 /dev/hdb7: Moved: 0.4%
  /dev/hdb7: Moved: 0.9%
  /dev/hdb7: Moved: 1.3%
  /dev/hdb7: Moved: 1.7%
  /dev/hdb7: Moved: 2.2%
  /dev/hdb7: Moved: 2.6%
  /dev/hdb7: Moved: 3.0%
  /dev/hdb7: Moved: 3.4%
  /dev/hdb7: Moved: 3.9%
  /dev/hdb7: Moved: 4.3%
  /dev/hdb7: Moved: 4.7%
  /dev/hdb7: Moved: 5.2%
  /dev/hdb7: Moved: 5.6%
  /dev/hdb7: Moved: 6.0%
  /dev/hdb7: Moved: 6.5%
  /dev/hdb7: Moved: 6.9%
  /dev/hdb7: Moved: 7.3%
  /dev/hdb7: Moved: 7.7%
  /dev/hdb7: Moved: 8.2%
  /dev/hdb7: Moved: 8.6%
  /dev/hdb7: Moved: 9.0%
  /dev/hdb7: Moved: 9.4%
  /dev/hdb7: Moved: 9.8%
  /dev/hdb7: Moved: 10.3%
  /dev/hdb7: Moved: 10.7%
  /dev/hdb7: Moved: 11.1%
  /dev/hdb7: Moved: 11.5%
  /dev/hdb7: Moved: 12.0%
  /dev/hdb7: Moved: 12.4%
  /dev/hdb7: Moved: 12.8%
  /dev/hdb7: Moved: 13.3%
  /dev/hdb7: Moved: 13.7%
  /dev/hdb7: Moved: 14.1%
  /dev/hdb7: Moved: 14.6%
  /dev/hdb7: Moved: 15.0%
  /dev/hdb7: Moved: 15.4%
  /dev/hdb7: Moved: 15.9%
  /dev/hdb7: Moved: 16.3%
  /dev/hdb7: Moved: 16.7%
  /dev/hdb7: Moved: 17.2%
  /dev/hdb7: Moved: 17.6%
  /dev/hdb7: Moved: 18.0%
  /dev/hdb7: Moved: 18.4%
  /dev/hdb7: Moved: 18.9%
  /dev/hdb7: Moved: 19.3%
  /dev/hdb7: Moved: 19.7%
  /dev/hdb7: Moved: 20.2%
  Updating volume group metadata
    Creating volume group backup "/etc/lvm/backup/myvg" (seqno 35).
    Found volume group "myvg"
    Found volume group "myvg"
    Suspending myvg-usr (254:0)
    Suspending myvg-pvmove0 (254:5)
    Found volume group "myvg"
    Found volume group "myvg"
    Suspending myvg-home (254:1)
    Suspending myvg-pvmove0 (254:5)
    Found volume group "myvg"
    Found volume group "myvg"
    Suspending myvg-opt (254:2)
    Suspending myvg-pvmove0 (254:5)
    Found volume group "myvg"
    Found volume group "myvg"
    Suspending myvg-var (254:3)