This is believed to be due to an accidental merge of some experimental code for asynchronous execution of ipvsadm commands some time back, and has caused pybal to fail to bring some services online in eqiad.
Example:
Nov 16 14:30:34 lvs1005 pybal[1943]: [pybal] ERROR: ipvsadm exited with status 255 when executing cmdlist ['-a -t 208.80.154.241:443 -r 10.64.0.107 -w 10\n', '-a -t 208.80.154.241:443 -r 10.64.0.106 -w 10\n', '-a -t 208.80.154.241:443 -r 10.64.32.133 -w 10\n', '-a -t 208.80.154.241:443 -r 10.64.32.134 -w 10\n'] Nov 16 14:30:34 lvs1005 pybal[1943]: [pybal] ERROR: ipvsadm stderr output: