3.简要介绍一下report obsolete命令 使用report obsolete命令报告过期备份
当手工删除了归档日志以后，rman备份会检测到日志缺失，从而无法进一步继续执行。
所以此时需要手工执行crosscheck过程，之后rman备份可以恢复正常。
1.crosscheck日志
$ rman target /
recovery manager: release 9.2.0.4.0 - 64bit production
copyright (c) 1995, 2002, oracle corporation. all rights reserved.
connected to target database: avatar2 (dbid=2480694409)
rman> crosscheck archivelog all;
using target database controlfile instead of recovery catalog
allocated channel: ora_disk_1
channel ora_disk_1: sid=25 devtype=disk
validation failed for archived log
archive log filename=/opt/oracle/oradata/avatar2/archive/1_2714.dbf recid=2702 stamp=545107659
validation failed for archived log
archive log filename=/opt/oracle/oradata/avatar2/archive/1_2715.dbf recid=2703 stamp=545108268
...........
validation failed for archived log
archive log filename=/opt/oracle/oradata/avatar2/archive/1_2985.dbf recid=2973 stamp=545399327
validation succeeded for archived log
archive log filename=/opt/oracle/oradata/avatar2/archive/1_2986.dbf recid=2974 stamp=545400820
validation succeeded for archived log
archive log filename=/opt/oracle/oradata/avatar2/archive/1_2987.dbf recid=2975 stamp=545401757
validation succeeded for archived log
archive log filename=/opt/oracle/oradata/avatar2/archive/1_2988.dbf recid=2976 stamp=545402716
validation succeeded for archived log
archive log filename=/opt/oracle/oradata/avatar2/archive/1_2989.dbf recid=2977 stamp=545403661
validation succeeded for archived log
archive log filename=/opt/oracle/oradata/avatar2/archive/1_2990.dbf recid=2978 stamp=545404946
validation succeeded for archived log
archive log filename=/opt/oracle/oradata/avatar2/archive/1_2991.dbf recid=2979 stamp=545406220
crosschecked 278 objects
rman>
2.使用delete expired archivelog all 命令删除所有过期归档日志：
rman> delete expired archivelog all;
released channel: ora_disk_1
allocated channel: ora_disk_1
channel ora_disk_1: sid=12 devtype=disk
list of archived log copies
key thrd seq s low time name
------- ---- ------- - --------- ----
376 1 2714 x 23-nov-04 =/opt/oracle/oradata/avatar2/archive/1_2714.dbf
.....
，