[root@galtest ~]# fdisk -l /dev/sda

Disk /dev/sda: 64.4 GB, 64424509440 bytes
64 heads, 32 sectors/track, 61440 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1         100      102384   83  Linux
/dev/sda2             101       61440    62812160   8e  Linux LVM

[root@galtest ~]# lvmdiskscan |grep sda
  /dev/sda1            [       99.98 MB]
  /dev/sda2            [       59.90 GB] LVM physical volume
[root@galtest ~]# vgs
  VG     #PV #LV #SN Attr   VSize  VFree
  vg00     1   8   0 wz--n- 59.88G 18.72G

[root@galtest ~]# df -h /dev/sda1
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1              97M   35M   58M  38% /boot

[root@galtest ~]# df -h /dev/sda2
Filesystem            Size  Used Avail Use% Mounted on
-                     2.8G   72K  2.8G   1% /dev

root@sysresccd /etc/lvm % fdisk -l /dev/sda

Disk /dev/sda: 42.9 GB, 42949672960 bytes
64 heads, 32 sectors/track, 40960 cylinders, total 83886080 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xeac5c5ef

   Device Boot      Start         End      Blocks   Id  System



root@sysresccd /etc/lvm % vgcreate vg00 /dev/sda
  No physical volume label read from /dev/sda
  Physical volume "/dev/sda" successfully created
  Volume group "vg00" successfully created

root@sysresccd /etc/lvm % vgs
  VG   #PV #LV #SN Attr   VSize  VFree
  vg00   1   0   0 wz--n- 40.00g 40.00g

root@sysresccd /etc/lvm % pvs
  PV         VG   Fmt  Attr PSize  PFree
  /dev/sda   vg00 lvm2 a--  40.00g 40.00g

root@sysresccd /etc/lvm % fdisk /dev/sda
Welcome to fdisk (util-linux 2.21.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0xa701bbb6.

Command (m for help): n
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): p
Partition number (1-4, default 1):
Using default value 1
First sector (2048-83886079, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-83886079, default 83886079): +100M
Partition 1 of type Linux and of size 100 MiB is set

Command (m for help): n
Partition type:
   p   primary (1 primary, 0 extended, 3 free)
   e   extended
Select (default p): p
Partition number (1-4, default 2):
Using default value 2
First sector (206848-83886079, default 206848):
Using default value 206848
Last sector, +sectors or +size{K,M,G} (206848-83886079, default 83886079):
Using default value 83886079
Partition 2 of type Linux and of size 39.9 GiB is set

Command (m for help): t
Partition number (1-4): 2
Hex code (type L to list codes): 8e
Changed system type of partition 2 to 8e (Linux LVM)

Command (m for help): a
Partition number (1-4): 1

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.


root@sysresccd /etc/lvm % fdisk -l /dev/sda

Disk /dev/sda: 42.9 GB, 42949672960 bytes
64 heads, 32 sectors/track, 40960 cylinders, total 83886080 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xa701bbb6

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      206847      102400   83  Linux
/dev/sda2          206848    83886079    41839616   8e  Linux LVM



root@sysresccd /etc/lvm % vgs
  No volume groups found