2012-07-04 04:30:47 CDT [26072]: [1-1] user=,db= FATAL: index "pg_attribute_relid_attnum_index" contains unexpected zero page at block 0
2012-07-04 04:30:47 CDT [26072]: [2-1] user=,db= HINT: Please REINDEX it.
Last option would be dump and restore. We need to avoid that reduce the downtime.
How about starting the instance with ignore_system_indexes=true ? And do dump & restore. Am not sure on this procedure. Should someone here would have better idea on this.