[linux-lvm] How can I expand a physical volume ?

[Massimiliano <max.fontana@email.it>]

Hi !
My first post here !
I've recently added a fourth Scsi Hard disk to my
Proliant ML350 configured as follow :
SmartArray Controller 641 with 3 72Gb Scsi h.disks.(raid5)
I installed on my Centos 4.2 the HP Array configuration Utility and did 
the following steps:
1) Expanded my array
2) Expanded my logical Volume
Everything ok . Now I can see 4 physical drives
and a new total space increased of 72gb(obviously..)
The problem is that the operating doesen't seem to recognize the new 
free space .
Here is the output of various command I tried :
--LVDISPLAY
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
LV UUID 0QlVVm-W4ZY-tSLv-syu6-qS6J-b2u9-2Ed13l
LV Write Access read/write
LV Status available
# open 1
LV Size 133,56 GB
Current LE 4274
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:0
********************
FDISK -l
Disk /dev/cciss/c0d0: 218.5 GB, 218501038080 bytes
255 heads, 63 sectors/track, 26564 cylinders
Units = cilindri of 16065 * 512 = 8225280 bytes

Dispositivo Boot Start End Blocks Id System
/dev/cciss/c0d0p1 * 1 13 104391 83 Linux
/dev/cciss/c0d0p2 14 17709 142143120 8e Linux LVM
**********************************
root@mail init.d]# pvdisplay
--- Physical volume ---
PV Name /dev/cciss/c0d0p2
VG Name VolGroup00
PV Size 135,53 GB / not usable 0
Allocatable yes
PE Size (KByte) 32768
Total PE 4337
Free PE 1
Allocated PE 4336
PV UUID XAEWQR-s1qj-Cj5K-gv0W-9ndt-lroN-35ZvNE
..........
[root@mail init.d]# vgdisplay -v
Finding all volume groups
Finding volume group "VolGroup00"
--- Volume group ---
VG Name VolGroup00
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size 135,53 GB
PE Size 32,00 MB
Total PE 4337
Alloc PE / Size 4336 / 135,50 GB
Free PE / Size 1 / 32,00 MB
VG UUID hVHrwV-Dt53-wbGa-ZwHQ-ZWcX-t5Tm-vQIVUu

--- Logical volume ---
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
LV UUID 0QlVVm-W4ZY-tSLv-syu6-qS6J-b2u9-2Ed13l
LV Write Access read/write
LV Status available
# open 1
LV Size 133,56 GB
Current LE 4274
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:0

--- Logical volume ---
LV Name /dev/VolGroup00/LogVol01
VG Name VolGroup00
LV UUID Apww83-TFLq-KqM9-zwEt-zPAW-a3J8-EPP8j7
LV Write Access read/write
LV Status available
# open 1
LV Size 1,94 GB
Current LE 62
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:1

--- Physical volumes ---
PV Name /dev/cciss/c0d0p2
PV UUID XAEWQR-s1qj-Cj5K-gv0W-9ndt-lroN-35ZvNE
PV Status allocatable
Total PE / Free PE 4337 / 1

It's clear that I have to expand the physical space but the only command 
I know ,PVRESIZE,
is not yet implemented but I know there is a workaround for it .
My last idea is to backup data and reinstall everything but , honestly , 
I'd prefer an alternative
solution . Consider that this server is already working in a production 
environment......
The workaround is based on using vgcfgbackup , edit the config file and 
vgcfgrestore . I know it's
a very dangerous operation and since I'm a very newbie to linux , I 
couldn't understand how
to modify the parameter pe_count (as indicated by the workaround) of the 
backed up
/etc/lvm/backup/VolGroup00 file . Here below u'll find the content of 
the above mentioned file.
How should I modify the pe_count value in order to use these added 72Gbs 
of new free space ?
Many many thanks in advance .
Max ( Italy )
*******************
# Generated by LVM2: Wed Dec 21 11:50:55 2005

contents = "Text Format Volume Group"
version = 1

description = "Created *after* executing 'vgcfgbackup'"

creation_host = "mail.laferspa.com"    # Linux mail.laferspa.com 
2.6.9-22.0.1.ELsmp #1 SMP Thu Oct 27 13:14:25 CDT 2005 i686
creation_time = 1135162255    # Wed Dec 21 11:50:55 2005

VolGroup00 {
  id = "hVHrwV-Dt53-wbGa-ZwHQ-ZWcX-t5Tm-vQIVUu"
  seqno = 3
  status = ["RESIZEABLE", "READ", "WRITE"]
  extent_size = 65536        # 32 Megabytes
  max_lv = 0
  max_pv = 0

  physical_volumes {

      pv0 {
          id = "XAEWQR-s1qj-Cj5K-gv0W-9ndt-lroN-35ZvNE"
          device = "/dev/cciss/c0d0p2"    # Hint only

          status = ["ALLOCATABLE"]
          pe_start = 384
          pe_count = 4337    # 135,531 Gigabytes
      }
  }

  logical_volumes {

      LogVol00 {
          id = "0QlVVm-W4ZY-tSLv-syu6-qS6J-b2u9-2Ed13l"
          status = ["READ", "WRITE", "VISIBLE"]
          segment_count = 1

          segment1 {
              start_extent = 0
              extent_count = 4274    # 133,562 Gigabytes

              type = "striped"
              stripe_count = 1    # linear

              stripes = [
                  "pv0", 0
              ]
          }
      }

      LogVol01 {
          id = "Apww83-TFLq-KqM9-zwEt-zPAW-a3J8-EPP8j7"
          status = ["READ", "WRITE", "VISIBLE"]
          segment_count = 1

          segment1 {
              start_extent = 0
              extent_count = 62    # 1,9375 Gigabytes

              type = "striped"
              stripe_count = 1    # linear

              stripes = [
                  "pv0", 4274
              ]
          }
      }
  }
}