Labor certificate (PERM) is for hiring a permanent worker (through applying for an immigration visa, i.e. employment-based green card). It is very difficult to justify to hire a 管家 as a permanent worker from another country because you have to convince USCIS that there is not a qualified one available in US. Here is a link for the employment-based green card categories:
http://www.uscis.gov/portal/site/uscis/menuitem.eb1d4c2a3e5b9ac89243c6a7543f6d1a/?vgnextoid=cdfd2f8b69583210VgnVCM100000082ca60aRCRD&vgnextchannel=cdfd2f8b69583210VgnVCM100000082ca60aRCRD