Verified (vdsm22-4.5-63.16.el5_6),
connectStoragePool failed --> 'StoragePoolMasterNotFound' exception thrown by vdsm : 

VDSM.LOG:
*********
Traceback (most recent call last):
  File "/usr/share/vdsm/storage/hsm.py", line 537, in public_connectStoragePool
    return pool.connect(hostID, scsiKey, msdUUID, masterVersion)
  File "/usr/share/vdsm/storage/sp.py", line 403, in connect
    SDF.refresh()
  File "/usr/share/vdsm/storage/sdf.py", line 85, in refresh
    cls.__sdc.refresh()
  File "/usr/share/vdsm/storage/sdc.py", line 140, in refresh
    self._refreshDomains()
  File "/usr/share/vdsm/storage/misc.py", line 722, in newfunc
    return self.__func(instance, *args, **kwargs)
  File "/usr/share/vdsm/storage/sdc.py", line 156, in _refreshDomains
    newdoms = (blockSD.getBlockStorageDomainList() +
  File "/usr/share/vdsm/storage/fileSD.py", line 355, in getFileStorageDomainList
    file = ros.glob(DOM_METAPATTERN)
  File "/usr/share/vdsm/storage/remoteFileHandler.py", line 180, in wrapper
    raise err
OSError: [Errno 62] Operation stuck on remote handler
Thread-236::ERROR::2011-02-09 12:11:14,385::misc::66::irs::Cannot find master domain: ('sp: 1712d17b-f591-4d4e-ac18-58777995e5c0 msd:c20dafa3-d4b9-40ea-8ec1-77ba376cda9e: Operation stuck on
 remote handler',)
Thread-236::ERROR::2011-02-09 12:11:14,385::misc::67::irs::Traceback (most recent call last):
  File "/usr/share/vdsm/storage/task.py", line 978, in _run
    return fn(*args, **kargs)
  File "/usr/share/vdsm/storage/hsm.py", line 551, in public_connectStoragePool
    raise lastException
StoragePoolMasterNotFound: Cannot find master domain: ('sp: 1712d17b-f591-4d4e-ac18-58777995e5c0 msd:c20dafa3-d4b9-40ea-8ec1-77ba376cda9e: Operation stuck on remote handler',)

    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
C: On Red Hat Enterprise Linux 5.6, using vdsm 2.2.6 with the NFS time-out fix the connectStoragePool and reconstructMaster functions were failing.
C: A valid response was not being returned to RHEVM, which was then giving a 'OSError: [Errno 62] Operation stuck on remote handler' error.
F: An error catcher was installed, and a valid exit code created.
R: If the error occurs, a useful error message is given.

Text: On Red Hat Enterprise Linux 5.6, using vdsm 2.2.6 with the NFS time-out fix the connectStoragePool and reconstructMaster functions were failing and returning an 'OSError: [Errno 62] Operation stuck on remote handler' error. An error catcher was installed, and when the error occurs now, a useful error message is given.

    Technical note updated. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    Diffed Contents:
@@ -3,4 +3,4 @@
 F: An error catcher was installed, and a valid exit code created.
 R: If the error occurs, a useful error message is given.
 
-Text: On Red Hat Enterprise Linux 5.6, using vdsm 2.2.6 with the NFS time-out fix the connectStoragePool and reconstructMaster functions were failing and returning an 'OSError: [Errno 62] Operation stuck on remote handler' error. An error catcher was installed, and when the error occurs now, a useful error message is given.+Text: Using VDSM with the NFS time-out fix, the connectStoragePool and reconstructMaster functions were failing and returning an 'OSError: [Errno 62] Operation stuck on remote handler' error. An error catcher was installed, and when the error occurs now, a useful error message is given.

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2011-0319.html