11.2rac中，snapshot controlfile位置一定要改到共享目录下

11.2rac中，snapshot controlfile位置一定要改到共享目录下，否则在rman备份时，会遇到（不是每次都遇到）如下错误：

[oracle@hosta logs]$ more backup_2015-08-31Recovery Manager: Release 11.2.0.4.0 - Production on Mon Aug 31 02:30:01 2015Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.connected to target database: orcl (DBID=987654321)RMAN> run2> {3> allocate channel ch1 type disk;4> allocate channel ch2 type disk;5> allocate channel ch3 type disk;6> allocate channel ch4 type disk;7> backup as compressed backupset database format '/rmanbackup/full_%U';8> crosscheck backup;9> delete obsolete;10> release channel ch1;11> release channel ch2;12> release channel ch3;13> release channel ch4;14> }15> using target database control file instead of recovery catalogallocated channel: ch1channel ch1: SID=912 instance=orcl1 device type=DISKallocated channel: ch2channel ch2: SID=939 instance=orcl1 device type=DISKallocated channel: ch3channel ch3: SID=1054 instance=orcl1 device type=DISKallocated channel: ch4channel ch4: SID=1268 instance=orcl1 device type=DISKStarting backup at 31-AUG-2015 02:30:04channel ch1: starting compressed full datafile backup setchannel ch1: specifying datafile(s) in backup setinput datafile file number=00001 name=+DATA/orcl/system01.dbfinput datafile file number=00005 name=+DATA/orcl/users02.dbfinput datafile file number=00009 name=+DATA/orcl/users06.dbfinput datafile file number=00013 name=+DATA/orcl/users09.dbfinput datafile file number=00019 name=+DATA/orcl/datafile/users.303.886806341channel ch1: starting piece 1 at 31-AUG-2015 02:30:05channel ch2: starting compressed full datafile backup setchannel ch2: specifying datafile(s) in backup setinput datafile file number=00003 name=+DATA/orcl/undotbs01.dbfinput datafile file number=00007 name=+DATA/orcl/users04.dbfinput datafile file number=00011 name=+DATA/orcl/orclusers05.dbfinput datafile file number=00015 name=+DATA/standby/datafile/undotbs2.292.880428203input datafile file number=00018 name=+DATA/orcl/datafile/system.300.886007889channel ch2: starting piece 1 at 31-AUG-2015 02:30:06channel ch3: starting compressed full datafile backup setchannel ch3: specifying datafile(s) in backup setinput datafile file number=00004 name=+DATA/orcl/users01.dbfinput datafile file number=00008 name=+DATA/orcl/users05.dbfinput datafile file number=00012 name=+DATA/orcl/users08.dbfinput datafile file number=00016 name=+DATA/orcl/datafile/users.304.886007045input datafile file number=00017 name=+DATA/orcl/datafile/users.297.886007285channel ch3: starting piece 1 at 31-AUG-2015 02:30:06channel ch4: starting compressed full datafile backup setchannel ch4: specifying datafile(s) in backup setinput datafile file number=00002 name=+DATA/orcl/sysaux01.dbfinput datafile file number=00006 name=+DATA/orcl/users03.dbfinput datafile file number=00010 name=+DATA/orcl/users07.dbfinput datafile file number=00014 name=+DATA/orcl/users10.dbfchannel ch4: starting piece 1 at 31-AUG-2015 02:30:07channel ch2: finished piece 1 at 31-AUG-2015 03:11:52piece handle=/rmanbackup/full_g1qfuntd_1_1 tag=TAG20150831T023005 comment=NONEchannel ch2: backup set complete, elapsed time: 00:41:46channel ch2: starting compressed full datafile backup setchannel ch2: specifying datafile(s) in backup setRMAN-03009: failure of backup command on ch2 channel at 08/31/2015 03:11:54ORA-00245: control file backup failed; target is likely on a local file systemcontinuing other job steps, job failed will not be re-runchannel ch2: starting compressed full datafile backup setchannel ch2: specifying datafile(s) in backup setincluding current SPFILE in backup setchannel ch2: starting piece 1 at 31-AUG-2015 03:11:54channel ch2: finished piece 1 at 31-AUG-2015 03:11:55piece handle=/rmanbackup/full_g5qfuqbq_1_1 tag=TAG20150831T023005 comment=NONEchannel ch2: backup set complete, elapsed time: 00:00:01channel ch4: finished piece 1 at 31-AUG-2015 03:33:29piece handle=/rmanbackup/full_g3qfunte_1_1 tag=TAG20150831T023005 comment=NONEchannel ch4: backup set complete, elapsed time: 01:03:22channel ch3: finished piece 1 at 31-AUG-2015 03:33:59piece handle=/rmanbackup/full_g2qfunte_1_1 tag=TAG20150831T023005 comment=NONEchannel ch3: backup set complete, elapsed time: 01:03:53channel ch1: finished piece 1 at 31-AUG-2015 03:43:29piece handle=/rmanbackup/full_g0qfuntd_1_1 tag=TAG20150831T023005 comment=NONEchannel ch1: backup set complete, elapsed time: 01:13:24released channel: ch1released channel: ch2released channel: ch3released channel: ch4RMAN-00571: ===========================================================RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============RMAN-00571: ===========================================================RMAN-03009: failure of backup command on ch2 channel at 08/31/2015 03:11:54ORA-00245: control file backup failed; target is likely on a local file systemRecovery Manager complete.

解决方法：

ORA-245: In RAC environment from 11.2onwards Backup Or Snapshot controlfile needs to be in shared location (文档 ID 1472171.1)

RMAN> CONFIGURE SNAPSHOT CONTROLFILE NAME TO '+FRA/snapcf_orcl.f';