SQL>  select * from gv$instance;

   INST_ID INSTANCE_NUMBER INSTANCE_NAME    HOST_ VERSION           STARTUP_T STATUS       PAR    THREAD# ARCHIVE LOG_SWITCH_
---------- --------------- ---------------- ----- ----------------- --------- ------------ --- ---------- ------- -----------
LOGINS     SHU DATABASE_STATUS   INSTANCE_ROLE      ACTIVE_ST
---------- --- ----------------- ------------------ ---------
         2               2 rac2             P61B  9.2.0.8.0         11-MAY-09 OPEN         YES          2 STOPPED
ALLOWED    NO  ACTIVE            PRIMARY_INSTANCE   NORMAL

         1               1 rac1             P61A  9.2.0.8.0         11-MAY-09 OPEN         YES          1 STOPPED
ALLOWED    NO  ACTIVE            PRIMARY_INSTANCE   NORMAL

SQL> select inst_id,open_mode from gv$database;

   INST_ID OPEN_MODE
---------- ----------
         1 READ WRITE
         2 READ WRITE

直接通过电源键关闭P61B

Mon May 11 21:22:01 2009
Reconfiguration started (old inc 5, new inc 6)
List of nodes:
 0
 Global Resource Directory frozen
one node partition
 Communication channels reestablished
 Master broadcasted resource hash value bitmaps
 Non-local Process blocks cleaned out
 Resources and enqueues cleaned out
 Resources remastered 622
 634 GCS shadows traversed, 0 cancelled, 38 closed
 429 GCS resources traversed, 0 cancelled
 3809 GCS resources on freelist, 4208 on array, 4208 allocated
 set master node info
 Submitted all remote-enqueue requests
 Update rdomain variables
 Dwn-cvts replayed, VALBLKs dubious
 All grantable enqueues granted
 634 GCS shadows traversed, 0 replayed, 38 unopened
 Submitted all GCS remote-cache requests
 0 write requests issued in 596 GCS resources
 1 PIs marked suspect, 0 flush PI msgs
Mon May 11 21:22:01 2009
Reconfiguration complete
 Post SMON to start 1st pass IR
Mon May 11 21:22:01 2009
Instance recovery: looking for dead threads
Mon May 11 21:22:01 2009
Beginning instance recovery of 1 threads
Mon May 11 21:22:01 2009
Started redo scan
Mon May 11 21:22:01 2009
Completed redo scan
 100 redo blocks read, 32 data blocks need recovery
Mon May 11 21:22:01 2009
Started recovery at
 Thread 2: logseq 4, block 2, scn 0.148534
Mon May 11 21:22:01 2009
Recovery of Online Redo Log: Thread 2 Group 4 Seq 4 Reading mem 0
  Mem# 0 errs 0: /dev/rtrac_redo2_21
Mon May 11 21:22:01 2009
Completed redo application
Mon May 11 21:22:01 2009
Ended recovery at
 Thread 2: logseq 4, block 102, scn 0.168687
 31 data blocks read, 34 data blocks written, 100 redo blocks read
Ending instance recovery of 1 threads
SMON: about to recover undo segment 11
SMON: mark undo segment 11 as available
SMON: about to recover undo segment 12
SMON: mark undo segment 12 as available
SMON: about to recover undo segment 13
SMON: mark undo segment 13 as available
SMON: about to recover undo segment 14
SMON: mark undo segment 14 as available
SMON: about to recover undo segment 15
SMON: mark undo segment 15 as available
SMON: about to recover undo segment 16
SMON: mark undo segment 16 as available
SMON: about to recover undo segment 17
SMON: mark undo segment 17 as available
SMON: about to recover undo segment 18
SMON: mark undo segment 18 as available
SMON: about to recover undo segment 19
SMON: mark undo segment 19 as available
SMON: about to recover undo segment 20
SMON: mark undo segment 20 as available

几乎是立即就查觉到了P61B宕机，马上把P61B踢出