Description of problem:
We're storing error strings as filesystem labels. This specific manifestation is a call to iutil.execWithCapture from isys._readFATLabel().

On ia64 systems with multiple PVs *or* multiple VGs, the following error dialog will halt any attempt to bring up the system in rescue mode:

      +----------------------+ Duplicate Labels +-----------------------+       
      |                                                                 |       
      | Multiple devices on your system are labelled Logical sector     |       
      | size is zero..  Labels across devices must be unique for your   |       
      | system to function properly.                                    |       
      |                                                                 |       
      | Please fix this problem and restart the installation process.   |       
      |                                                                 |       
      |                           +--------+                            |       
      |                           | Reboot |                            |       
      |                           +--------+                            |       
      |                                                                 |       
      |                                                                 |       
      +-----------------------------------------------------------------+       

The basic problem is that iutil.execWithCapture makes no use of the stderr input argument and instead always dupes stderr to stdout. So, when dosfslabel throws an error to stdout trying to read a fat label from a PV, we end up thinking the PV has a label of "Logical sector size is zero." Another one is a VG with a label of "Read 512 bytes at 0:Is a directory".

Callers who want stderr duped to stdout should use execWithCapture(...,stderr=1).

Version-Release number of selected component (if applicable):
anaconda-11.1.2.136-2

How reproducible:
Always

Steps to Reproduce:
1. create a partition that doesn't contain any fslabel
2. call isys._readFATLabel (or, on ia64, isys.readFSLabel) on the device

-OR-
1. try to rescue an ia64 box containing more than one PV or more than one VG
  
Actual results:
An error string is returned as though it was a label, or an error indicating rescue mode is aborting.

Expected results:
No return value if no label is present, and successful rescue of systems we installed.

Additional info:
This only causes problems on ia64, but that's only because we don't collect FAT labels on other arches.