DRBD + Corosync + Pacemaker를 잘 설명한 글
http://everydayminder.wordpress.com/2014/05/21/drbd-pacemaker-corosync-%EA%B8%B0%EB%B0%98-postgresql-ha-%EA%B5%AC%EC%84%B1%ED%99%98%EA%B2%BD-%EC%84%A4%EC%A0%95/
Corosync 관련 글
http://ogervasi.unipg.it/OpSysNet/4Students/Clusters/corosync-datasheet-2009.pdf
https://www.kernel.org/doc/ols/2008/ols2008v1-pages-85-100.pdf