问题描述
通过rman进行异机恢复参数文件时，提示如下错误：
RMAN> restore spfile from autobackup;Starting restore at 16-AUG-14using channel ORA_DISK_1channel ORA_DISK_1: looking for AUTOBACKUP on day: 0816channel ORA_DISK_1: looking for AUTOBACKUP on day: 0815channel ORA_DISK_1: looking for AUTOBACKUP on day: 0814channel ORA_DISK_1: looking for AUTOBACKUP on day: 0813channel ORA_DISK_1: looking for AUTOBACKUP on day: 0812channel ORA_DISK_1: looking for AUTOBACKUP on day: 0811channel ORA_DISK_1: looking for AUTOBACKUP on day: 0810channel ORA_DISK_1: no AUTOBACKUP in 7 days foundRMAN-00571: ===========================================================RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============RMAN-00571: ===========================================================RMAN-03002: failure of restore command at 08/16/ 03:39:24RMAN-06172: no AUTOBACKUP found or specified handle is not a valid copy or piece
问题原因
（1）rman中没有配置configure controlfile autobackup on
RMAN> show all;RMAN configuration parameters for database with db_unique_name DUMMY are:CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # defaultCONFIGURE BACKUP OPTIMIZATION OFF; # defaultCONFIGURE DEFAULT DEVICE TYPE TO DISK; # defaultCONFIGURE CONTROLFILE AUTOBACKUP ON; # defaultCONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # defaultCONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # defaultCONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # defaultCONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # defaultCONFIGURE MAXSETSIZE TO UNLIMITED; # defaultCONFIGURE ENCRYPTION FOR DATABASE OFF; # defaultCONFIGURE ENCRYPTION ALGORITHM 'AES128'; # defaultCONFIGURE COMPRESSION ALGORITHM 'BASIC' AS OF RELEASE 'DEFAULT' OPTIMIZE FOR LOAD TRUE ; # defaultCONFIGURE RMAN OUTPUT TO KEEP FOR 7 DAYS; # defaultCONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default
（2）rman默认查找7天内的备份，如果7天之内没有发生自动备份，那么rman也将无法找到自动备份。
遇到这种情况一般有两种解决方式：
① restore spfile from autobackup until time ‘SYSDATE-N’;
② restore spfile from autobackup maxdays N;
（3）第三种情况就是上篇试验中遇到的。由于autobackup的默认设置发生了变化，也就是说，原来我们已经设置了"configure controlfile autobackup on"；但是再重新使用rman进行spfile的恢复时，这个设置已经变成了off了。这种情况在错误中不会提示，所以较难发现。出现这种情况是由于目前数据库只是通过rman的默认设置启动，而且处在nomount状态。解决的方法是找到自动备份的路径，直接将路径告诉rman。
RMAN> restore spfile from '/orabk/ctrl_c-2363318542-0222-02';Starting restore at 23-FEB-21using channel ORA_DISK_1channel ORA_DISK_1: restoring spfile from AUTOBACKUP /orabk/ctrl_c-2363318542-0222-02channel ORA_DISK_1: SPFILE restore from AUTOBACKUP completeFinished restore at 23-FEB-21
