[oracle@TestXLink dbs]$ sqlplus /nolog

SQL*Plus: Release 11.2.0.1.0 Production on Wed Mar 14 23:17:54 2012

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SQL> conn /as sysasm
Connected to an idle instance.
SQL> startup mount
ASM instance started

Total System Global Area  284565504 bytes
Fixed Size                  1336036 bytes
Variable Size             258063644 bytes
ASM Cache                  25165824 bytes
ORA-15032: not all alterations performed
ORA-15017: diskgroup "DATA" cannot be mounted
ORA-15063: ASM discovered an insufficient number of disks for diskgroup "

SQL> col path for a30  
SQL> set lines 100
SQL> select mode_status,name,state,path from v$asm_disk;

MODE_ST NAME                           STATE    PATH
------- ------------------------------ -------- ------------------------------
ONLINE                                 NORMAL   /dev/raw/raw4
ONLINE                                 NORMAL   /dev/raw/raw2
ONLINE                                 NORMAL   /dev/raw/raw5
ONLINE                                 NORMAL   /dev/raw/raw3
ONLINE                                 NORMAL   /dev/raw/raw1
SQL> select * from v$asm_diskgroup
  2  ;
no rows selected
SQL> show parameter asm_disk
NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
asm_diskgroups                       string      DATA
asm_diskstring                       string      /dev/raw/raw*
SQL> 

以下的asm实例的日志
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Production
"alert_+ASM.log" 1376L, 59479C                                                                                                                                 1286,1        95%
  asm_diskstring           = "/dev/raw/raw*"
  asm_diskgroups           = "DATA"
  asm_power_limit          = 1
  diagnostic_dest          = "/u01/app/oracle/"
Wed Mar 14 23:18:07 2012
PMON started with pid=2, OS id=4493
Wed Mar 14 23:18:07 2012
VKTM started with pid=3, OS id=4495 at elevated priority
VKTM running at (10)millisec precision with DBRM quantum (100)ms
Wed Mar 14 23:18:07 2012
GEN0 started with pid=4, OS id=4499
Wed Mar 14 23:18:07 2012
DIAG started with pid=5, OS id=4501
Wed Mar 14 23:18:07 2012
PSP0 started with pid=6, OS id=4503
Wed Mar 14 23:18:07 2012
DIA0 started with pid=7, OS id=4505
Wed Mar 14 23:18:07 2012
MMAN started with pid=8, OS id=4507
Wed Mar 14 23:18:07 2012
DBW0 started with pid=9, OS id=4509
Wed Mar 14 23:18:07 2012
LGWR started with pid=10, OS id=4511
Wed Mar 14 23:18:07 2012
CKPT started with pid=11, OS id=4513
Wed Mar 14 23:18:07 2012
SMON started with pid=12, OS id=4515
Wed Mar 14 23:18:07 2012
RBAL started with pid=13, OS id=4517
Wed Mar 14 23:18:07 2012
GMON started with pid=14, OS id=4519
Wed Mar 14 23:18:07 2012
MMON started with pid=15, OS id=4521
Wed Mar 14 23:18:07 2012
MMNL started with pid=16, OS id=4523
ORACLE_BASE from environment = /u01/app/oracle
Wed Mar 14 23:18:07 2012
SQL> ALTER DISKGROUP ALL MOUNT
NOTE: Diskgroups listed in ASM_DISKGROUPS are
         DATA
NOTE: cache registered group DATA number=1 incarn=0xbc9dab97
NOTE: cache began mount (first) of group DATA number=1 incarn=0xbc9dab97
ERROR: no PST quorum in group: required 2, found 0
NOTE: cache dismounting (clean) group 1/0xBC9DAB97 (DATA)
NOTE: dbwr not being msg'd to dismount
NOTE: lgwr not being msg'd to dismount
NOTE: cache dismounted group 1/0xBC9DAB97 (DATA)
NOTE: cache ending mount (fail) of group DATA number=1 incarn=0xbc9dab97
kfdp_dismount(): 2
kfdp_dismountBg(): 2
ERROR: diskgroup DATA was not mounted
NOTE: cache deleting context for group DATA 1/-1130517609
ORA-15032: not all alterations performed
ORA-15017: diskgroup "DATA" cannot be mounted
ORA-15063: ASM discovered an insufficient number of disks for diskgroup "DATA"
ERROR: ALTER DISKGROUP ALL MOUNT