problems with basic lvm commands on Debian

[Faheem Mitha <faheem@email.unc.edu>]

Dear People,

I must be missing something obvious, but I'm having problems with basic 
commands on Debian Sarge, using lvm2.

I installed lvm2 and dmsetup. I'm using the stock Debian kernel 2.6.8-2-386.

I can do basic manipulations using /dev/hda1, but not with /dev/hda2.

This is on a very ordinary Dell Optiplex, normal x86 architecture.

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root@io:/home/faheem# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/hda2             37483592    300352  35279136   1% /
tmpfs                   258052         0    258052   0% /dev/shm
/dev/hda1               918322     14622    854704   2% /boot

  Physical volume "/dev/hda2" successfully created

root@io:/dev/mapper# pvcreate /dev/hda1

root@io:/dev/mapper# pvdisplay /dev/hda1
  --- Physical volume ---
  PV Name               /dev/hda1
  VG Name               testvg
  PV Size               956.00 MB / not usable 0
  Allocatable           yes
  PE Size (KByte)       4096
  Total PE              239
  Free PE               239
  Allocated PE          0
  PV UUID               sGOTrW-ttC4-m4uq-Cwck-V5s3-knz7-NpydvJ

root@io:/dev/mapper# vgcreate testvg /dev/hda1
  Volume group "testvg" successfully created
root@io:/dev/mapper# vgdisplay testvg
  --- Volume group ---
  VG Name               testvg
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  1
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                0
  Open LV               0
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               956.00 MB
  PE Size               4.00 MB
  Total PE              239
  Alloc PE / Size       0 / 0
  Free  PE / Size       239 / 956.00 MB
  VG UUID               IHrOgz-RWDW-EIAY-m9vD-idgT-1I99-cyoS8n

root@io:/dev/mapper# pvcreate /dev/hda2
  Physical volume "/dev/hda2" successfully created

All good so far. However.

root@io:/dev/mapper# pvdisplay /dev/hda2
  No physical volume label read from /dev/hda2
  Failed to read physical volume "/dev/hda2"

root@io:/home/faheem# vgextend testvg  /dev/hda2
  No physical volume label read from /dev/hda2
  /dev/hda2 not identified as an existing physical volume
  Unable to add physical volume '/dev/hda2' to volume group 'testvg'.

Any idea what is going on here? This is a new installation, and only has the 
bare bones on it.

Please cc me on any reply. Thanks in advance.

                                                     Faheem.