RHEV: Host "Non Responsive", vdsmd on host crashing, "misc::100::irs::FAILED: <err> = Password:" in vdsm.log

Issue

• A RHEV host has stopped responding (set in the Admin GUI to "Non Responsive").

• On the host, the vdsmd daemon keeps crashing, writing something like the following in /var/log/vdsm/vdsm.log:

  MainThread::ERROR::2009-11-30 14:49:50,098::vdsmd_content::190::vds::VDSMD crashed immediately - ( < 2 sec) exiting without recovering
  MainThread::INFO::2009-12-01 11:55:39,416::vdsmd_content::168::vds::After daemonize - My pid is 6099
  MainThread::INFO::2009-12-01 11:55:39,428::vdsmd_content::179::vds::I am Watchdog - vdsm pid is 6106
  MainThread::INFO::2009-12-01 11:55:39,427::vdsmd_content::194::vds::I am the actual vdsmd
  MainThread::DEBUG::2009-12-01 11:55:39,805::misc::76::irs::['sudo', '/usr/sbin/vgs', '--noheadings', '-o', 'vg_name,vg_uuid,vg_size,vg_free,vg_extent_size,vg_extent_count,tags', '--nosuffix', '--units', 'b'M] (cwd None)
  MainThread::WARNING::2009-12-01 11:55:41,851::misc::100::irs::FAILED: <err> = Password: 
  ; <rc> = 1