rman备份db时出现了：waiting for snapshot control file enqueue提示，很少看到这个提示，记录一下。
RMAN> run{
2> backup database;
3> delete noprompt obsolete;
4> backup archivelog all;
5> }
Starting backup at 2011-09-30 15:31:00
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00001 name=G:ORACLEPRODUCT10.2.0ORADATAORCLSYSTEM01.DBF
input datafile fno=00003 name=G:ORACLEPRODUCT10.2.0ORADATAORCLSYSAUX01.DBF
input datafile fno=00004 name=G:ORACLEPRODUCT10.2.0ORADATAORCLUSERS01.DBF
input datafile fno=00005 name=G:ORACLEPRODUCT10.2.0ORADATAORCLTEST.DBF
input datafile fno=00006 name=G:ORACLEPRODUCT10.2.0ORADATAORCLUNDOTBS02.DBF
channel ORA_DISK_1: starting piece 1 at 2011-09-30 15:31:05
channel ORA_DISK_1: finished piece 1 at 2011-09-30 15:31:40
piece handle=G:ORACLEPRODUCT10.2.0FLASH_RECOVERY_AREAORCLBACKUPSET2011_09_30O1_MF_NNNDF_TAG20110930T153101_78BW1SH4_.BKP tag=TAG20110930T153101 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:36
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
waiting for snapshot control file enqueue
including current control file in backupset
including current SPFILE in backupset
channel ORA_DISK_1: starting piece 1 at 2011-09-30 15:32:25
channel ORA_DISK_1: finished piece 1 at 2011-09-30 15:32:26
本文URL地址：http://www.bianceng.cn/database/Oracle/201410/45566.htm
piece handle=G:ORACLEPRODUCT10.2.0FLASH_RECOVERY_AREAORCLBACKUPSET2011_09_30O1_MF_NCSNF_TAG20110930T153101_78BW49QG_.BKP tag=TAG20110930T153101 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:45
Finished backup at 2011-09-30 15:32:26
RMAN retention policy will be applied to the command
RMAN retention policy is set to recovery window of 7 days
using channel ORA_DISK_1
no obsolete backups found
Starting backup at 2011-09-30 15:32:30
current log archived
using channel ORA_DISK_1
channel ORA_DISK_1: starting archive log backupset
channel ORA_DISK_1: specifying archive log(s) in backup set
input archive log thread=1 sequence=71 recid=101 stamp=762189937
input archive log thread=1 sequence=72 recid=102 stamp=763227110
input archive log thread=1 sequence=73 recid=103 stamp=763227151
channel ORA_DISK_1: starting piece 1 at 2011-09-30 15:32:32
channel ORA_DISK_1: finished piece 1 at 2011-09-30 15:32:33
piece handle=G:ORACLEPRODUCT10.2.0FLASH_RECOVERY_AREAORCLBACKUPSET2011_09_30O1_MF_ANNNN_TAG20110930T153231_78BW4JPG_.BKP tag=TAG20110930T153231 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:02
Finished backup at 2011-09-30 15:32:33
RMAN>
--===================================
搜了一下doc的解释是：
Backup Fails Because of Control File Enqueue: Scenario
In this scenario, a backup job fails because RMAN cannot make a snapshot control file. The message stack is as follows:
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================