求救，centos下，ORACLE无法启动

错误日志如下Mon Jun 20 10:11:23 2011
Starting ORACLE instance (normal)
LICENSE_MAX_SESSION = 0
LICENSE_SESSIONS_WARNING = 0
Picked latch-free SCN scheme 2
Using LOG_ARCHIVE_DEST_10 parameter default value as USE_DB_RECOVERY_FILE_DEST
Autotune of undo retention is turned on. 
IMODE=BR
ILAT =18
LICENSE_MAX_USERS = 0
SYS auditing is disabled
ksdpec: called for event 13740 prior to event group initialization
Starting up ORACLE RDBMS Version: 10.2.0.1.0.
System parameters with non-default values:
  processes                = 150
  __shared_pool_size       = 184549376
  __large_pool_size        = 16777216
  __java_pool_size         = 16777216
  __streams_pool_size      = 0
  sga_target               = 1124073472
  control_files            = /u01/app/oracle/oradata/orcl/control01.ctl, /u01/app/oracle/oradata/orcl/control02.ctl, /u01/app/oracle/oradata/orcl/control03.ctl
  db_block_size            = 8192
  __db_cache_size          = 889192448
  compatible               = 10.2.0.1.0
  db_file_multiblock_read_count= 16
  db_recovery_file_dest    = /u01/app/oracle/flash_recovery_area/
  db_recovery_file_dest_size= 2147483648
  undo_management          = AUTO
  undo_tablespace          = UNDOTBS1
  remote_login_passwordfile= EXCLUSIVE
  db_domain                = 
  dispatchers              = (PROTOCOL=TCP) (SERVICE=orclXDB)
  job_queue_processes      = 0
  background_dump_dest     = /u01/app/oracle/admin/orcl/bdump
  user_dump_dest           = /u01/app/oracle/admin/orcl/udump
  core_dump_dest           = /u01/app/oracle/admin/orcl/cdump
  audit_file_dest          = /u01/app/oracle/admin/orcl/adump
  db_name                  = orcl
  open_cursors             = 300
  pga_aggregate_target     = 371195904
  aq_tm_processes          = 0
USER: terminating instance due to error 27103
Instance terminated by USER, pid = 3891