Jerry, I tried as you said with the parameter recovery_target_timeline = 'latest' and it works.
I tried on a smaller test database (only 15MB) with PG9.1.1 and only 1 slave.
My switchover procedure was :
Step 1 : stop the old master /usr/local/pgsql/bin/pg_ctl stop -m immediate -D /usr/local/pgsql91/server1/data
Step 2 : promote slave as master : touch /usr/local/pgsql91/server2/data/trigger_file
Step 3 : declare the old master as a standby server Step 3.1 : vi /usr/local/pgsql91/server1/data/postgresql.conf Add hot_standby = on in the postgresql.conf
Step 3.2 Set recovery.conf for old master server (including recovery_target_timeline = 'latest') cp /usr/local/pgsql91/server1/data/recovery.bkp /usr/local/pgsql91/server1/data/recovery.conf