From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; .NET CLR 
1.0.3705)

Description of problem:
Bad: The installation cannot go on.

Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1.Begin the installation.
2.After choosing how to deal with creating partitions,the Bug comes.
3.
	

Additional info:

Traceback (most recent call last):
  File "/usr/lib/anaconda/gui.py", line 632, in nextClicked
    self.dispatch.gotoNext()
  File "/usr/lib/anaconda/dispatch.py", line 150, in gotoNext
    self.moveStep()
  File "/usr/lib/anaconda/dispatch.py", line 215, in moveStep
    rc = apply(func, self.bindArgs(args))
  File "/usr/lib/anaconda/partitioning.py", line 57, in partitionObjectsInitialize
    partitions.setFromDisk(diskset)
  File "/usr/lib/anaconda/partitions.py", line 184, in setFromDisk
    lvm.vgscan()
  File "/usr/lib/anaconda/lvm.py", line 38, in vgscan
    raise SystemError, "vgscan failed"
SystemError: vgscan failed

Local variables in innermost frame:
rc: 24320


Dispatcher instance, containing members:
method: CdromInstallMethod instance, containing members:
  messageWindow: <bound method InstallInterface.messageWindow of 
<gui.InstallInterface instance at 0x868b2cc>>
  loopbackFile: None
  progressWindow: <bound method InstallInterface.progressWindow of 
<gui.InstallInterface instance at 0x868b2cc>>
  device: hdc
  tree: /mnt/source
  rootPath: /mnt/sysimage
  currentDisc: [1]
step: 9
intf: InstallInterface instance, containing members:
  icw: InstallControlWindow instance, containing members:
    displayHelp: 1
    stockButtons: (('gtk-go-back', 'prevButtonStock', '_Back', <bound method 
InstallControlWindow.prevClicked of <gui.InstallControlWindow instance at 
0x830cffc>>), ('gtk-go-forward', 'nextButtonStock', '_Next', <bound method 
InstallControlWindow.nextClicked of <gui.InstallControlWindow instance at 
0x830cffc>>), ('gtk-new', 'releaseButton', '_Release Notes', <bound method 
InstallControlWindow.releaseClicked of <gui.InstallControlWindow instance at 
0x830cffc>>), ('gtk-help', 'showHelpButton', 'Show _Help', <bound method 
InstallControlWindow.helpClicked of <gui.InstallControlWindow instance at 
0x830cffc>>), ('gtk-help', 'hideHelpButton', 'Hide _Help', <bound method 
InstallControlWindow.helpClicked of <gui.InstallControlWindow instance at 
0x830cffc>>), ('gtk-execute', 'debugButton', '_Debug', <bound method 
InstallControlWindow.debugClicked of <gui.InstallControlWindow instance at 
0x830cffc>>))
    handle: 1155
    help: <TextViewBrowser object (GtkTextView) at 0x85f4074>
    buttonBox: <gtk.HButtonBox object (GtkHButtonBox) at 0x85f605c>
    hideHelpButton: <gtk.Button object (GtkButton) at 0x84db4b4>
    nextButtonStock: <gtk.Button object (GtkButton) at 0x848f26c>
    help_sw: <gtk.ScrolledWindow object (GtkScrolledWindow) at 0x82bfc04>
    dir: 1
    dispatch: Already dumped
  reloadRcQueued: 0
    ii: Already dumped
    currentWindow: PartitionMethodWindow instance, containing members:
      ics: InstallControlState instance, containing members:
        nextButtonLabel: None
        helpButtonEnabled: 1
        searchPath: [./, /usr/share/anaconda/, ./]
        prevButtonLabel: None
        grabNext: 0
        title: g:>d=:f4i??e0/?e	'??#013;
        nextButtonInfo: None
        prevEnabled: 1
        html: 
        helpEnabled: 3
        nextEnabled: 1
        htmlFile: howpartition
        prevButton: gtk-prev
        cw: Already dumped
        nextButton: gtk-next
      useDS: <gtk.RadioButton object (GtkRadioButton) at 0x849d7b4>
      useFdisk: <gtk.RadioButton object (GtkRadioButton) at 0x86fa41c>
      useAuto: <gtk.RadioButton object (GtkRadioButton) at 0x88015a4>
      partitions: Partitions instance, containing members:
        useFdisk: 0
        useAutopartitioning: 1
        autoClearPartType: 2
        nextUniqueID: 6
        reinitializeDisks: 0
        autoClearPartDrives: []
        zeroMbr: 0
        isKickstart: 0
        requests: [PreexistingPartitionSpec instance, containing members:
          currentDrive: None
          badblocks: None
          format: None
          migrate: None
          origfstype: None
          primary: None
          fstype: None
          preexist: 1
          dev: None
          uniqueID: 2
          device: hda2
          mountpoint: None
          requestSize: 36005.0537109
          maxSizeMB: None
          size: 36005.0537109
          end: 94221224