[oracle@hear adump]$ rman target /
Recovery Manager: Release 11.2.0.4.0 - Production on Mon Jun 17 04:28:58 2019
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
connected to target database: HEARDB (DBID=3039837723)
RMAN> backup archivelog all delete all input;
Starting backup at 17-JUN-19
current log archived
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=3400 device type=DISK
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of backup command at 06/17/2019 04:29:27
RMAN-06059: expected archived log not found, loss of archived log compromises recoverability
ORA-19625: error identifying file /home/oracle/app/oracle/product/11.2.0/dbhome_1/dbs/arch1_9_1010111956.dbf
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
原因在于操作系统下删除了这个归档日志，这个日志还没备份过，rman去备份的时候，找不到这个归档就出错了。可用以下方法解决：
RMAN> change archivelog all crosscheck;
当手工删除了数据库的归档文件后，需要用这个命令进行同步。
（物理上删除了归档日志，但是控制文件并不知道；因此需要交叉检验以同步信息）
crosscheck archivelog all;
RMAN> crosscheck archivelog all;
重新备份归档日志:
RMAN> backup archivelog all format '/home/oracle/backup/rman_arch_%T_%u';
Starting backup at 17-JUN-19
current log archived
using channel ORA_DISK_1
channel ORA_DISK_1: starting archived log backup set
channel ORA_DISK_1: specifying archived log(s) in backup set
input archived log thread=1 sequence=14 RECID=23 STAMP=1011154964
input archived log thread=1 sequence=15 RECID=24 STAMP=1011155367
input archived log thread=1 sequence=16 RECID=25 STAMP=1011155460
channel ORA_DISK_1: starting piece 1 at 17-JUN-19
channel ORA_DISK_1: finished piece 1 at 17-JUN-19
piece handle=/home/oracle/backup/rman_arch_20190617_0qu4a0g5 tag=TAG20190617T043100 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 17-JUN-19