告警日志提示的错误信息：

Linux-x86_64 Error: 21: Is a directory

Fri Dec 11 08:54:36 2015

Errors in file /u01/app/oracle/diag/rdbms/jzfpdb/jzfpdb1/trace/jzfpdb1_m000_3150.trc:

ORA-01580: error creating control backup file /u01/app/oracle/11.2.0/db/dbs/

ORA-27056: could not delete file

Linux-x86_64 Error: 21: Is a directory

Errors in file /u01/app/oracle/diag/rdbms/jzfpdb/jzfpdb1/trace/jzfpdb1_m000_3150.trc:

ORA-01580: error creating control backup file /u01/app/oracle/11.2.0/db/dbs/

ORA-27056: could not delete file

Linux-x86_64 Error: 21: Is a directory

根据报错的信息，该错误是一个控制文件备份错误的问题，进入rman环境下，备份控制文件：

RMAN> backup current controlfile;

Starting backup at 11-DEC-15

using target database control file instead of recovery catalog

allocated channel: ORA_DISK_1

channel ORA_DISK_1: SID=3537 instance=jzfpdb1 device type=DISK

channel ORA_DISK_1: starting full datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

RMAN-00571: ===========================================================

RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============

RMAN-00571: ===========================================================

RMAN-03009: failure of backup command on ORA_DISK_1 channel at 12/11/2015 11:24:10

ORA-01580: error creating control backup file /u01/app/oracle/11.2.0/db/dbs/

ORA-27056: could not delete file

Linux-x86_64 Error: 21: Is a directory

可以看到，报出跟日志中同样的错误，说明问题的原因就在备份控制文件这个点上，查看rman备份参数：

RMAN> show all;

RMAN configuration parameters for database with db_unique_name JZFPDB are:

CONFIGURE RETENTION POLICY TO REDUNDANCY 2;

CONFIGURE BACKUP OPTIMIZATION OFF; # default

CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default

CONFIGURE CONTROLFILE AUTOBACKUP ON;

CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/backup/%F';

CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default

CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default

CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default

CONFIGURE MAXSETSIZE TO UNLIMITED; # default

CONFIGURE ENCRYPTION FOR DATABASE OFF; # default

CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default

CONFIGURE COMPRESSION ALGORITHM 'BASIC' AS OF RELEASE 'DEFAULT' OPTIMIZE FOR LOAD TRUE ; # default

CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON STANDBY;

CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/u01/app/oracle/11.2.0/db/dbs/';

可以看到snapshot controlfile name参数的值指向了日志中错误提示出来的路径，从路径的目录来看，该参数指向的是一个文件夹目录，这是不正确的，一般情况下，该参数指向的应该是一个文件的绝对路径并且是指定文件名的，那么，我们尝试通过这种思路去解决这个问题，

在rman环境下修改snapshot controlfile name的值：

RMAN> configure snapshot  controlfile name to '/u01/app/oracle/11.2.0/db/dbs/snapcf_jzfpdb1.f';

old RMAN configuration parameters:

CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/u01/app/oracle/11.2.0/db/dbs/';

new RMAN configuration parameters:

CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/u01/app/oracle/11.2.0/db/dbs/snapcf_jzfpdb1.f';

new RMAN configuration parameters are successfully stored

可以看到参数设置已成功的保存，接着我们在测试一下看是不是这个原因，用同样的方法备份控制文件：

RMAN> backup current controlfile;

Starting backup at 11-DEC-15

using channel ORA_DISK_1

channel ORA_DISK_1: starting full datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

including current control file in backup set

channel ORA_DISK_1: starting piece 1 at 11-DEC-15

channel ORA_DISK_1: finished piece 1 at 11-DEC-15

piece handle=+FRA/jzfpdb/backupset/2015_12_11/ncnnf0_tag20151211t112709_0.760.898169231 tag=TAG20151211T112709 comment=NONE

channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01

Finished backup at 11-DEC-15

Starting Control File and SPFILE Autobackup at 11-DEC-15

piece handle=/backup/c-1095298896-20151211-00 comment=NONE

Finished Control File and SPFILE Autobackup at 11-DEC-15

可以看到，控制文件已成功备份，没有再报出先前备份控制文件的错误，监控数据库告警日志文件，再也没发现有错误描述所报的错误。