Oracle入门教程：RMAN备份归档日志的注意要点

今天在公司的数据库上看到这样的一个RMAN备份脚本： run { allocate channel c1 type disk maxpiecesize = 2G; allocate channel

今天在公司的数据库上看到这样的一个RMAN备份脚本：

run {
allocate channel c1 type disk maxpiecesize = 2G;
allocate channel c2 type disk maxpiecesize = 2G;
backup incremental level 1 database format '/backup/osedb_osedb01/data/%d_DF_%T_%s_%p.bak'
plus archivelog format '/backup/osedb_osedb01/arch/%d_AF_%T_%s_%p.log' all delete all input;
release channel c1;
release channel c2;
}

注意上面红色字体部分。我一看，感觉好像有些问题，于是在测试机上做了一下试验，，发现果然是有错误的。下面进行详细说明。

1. 首先，上面的脚本是错误的，应该将上面红色字体的第一个"all"去掉即可。

2. delete input和delete all input的区别

（1）如果归档日志目录只是一个时，即归档时只有一份归档日志时，上面的两种写法是没有区别的；

（2）如果归档日志目录有多个时，即归档时保存有多份归档日志时，那么：

delete input当备份了归档日志后，会删除第一个归档目录（如：log_archive_dest_1）下的所有归档日志；

delete all input则在备份了归档日志后，所有所有log_archive_dest_n中的备份的archivelog都会被删除。

3. 那么，至于什么时候可以使用all delete input或all delete all input呢？

在1，2小点中提到的写法都是在备份数据库时顺便备份归档日志的写法，如：

backup database plus archivelog delete all input;

而使用all delete all input是直接专门对数据库归档日志进行备份时使用，如：

backup archivelog all delete all input;

附加：

当在备份归档日志时，如果有些归档日志被删除了或是丢失了，那么在备份过程就就会报错RMAN-06059：

假如现数据库有如下的归档日志：

RMAN> list archivelog all;

List of Archived Log Copies

Key Thrd Seq S Low Time Name

------- ---- ------- - --------- -------------

59 1 35 A 16-MAY-11 /u01/backup/arch1/1_35_750725106.dbf

60 1 35 A 16-MAY-11 /u01/backup/arch2/1_35_750725106.dbf

61 1 36 A 16-MAY-11 /u01/backup/arch1/1_36_750725106.dbf

62 1 36 A 16-MAY-11 /u01/backup/arch2/1_36_750725106.dbf

现在手工在操作系统下用rm命令将36号归档日志文档删除，模拟36号归档日志丢失了，那么在执行备份归档日志时将出现：

RMAN> backup tablespace app plus archivelog delete all input;

Starting backup at 16-MAY-11

current log archived

using channel ORA_DISK_1

archived log /u01/backup/arch1/1_36_750725106.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 36

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

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

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

RMAN-03002: failure of backup plus archivelog command at 05/16/2011 03:22:29

RMAN-06059: expected archived log not found, lost of archived log compromises recoverability

ORA-19625: error identifying file /u01/backup/arch2/1_36_750725106.dbf

ORA-27037: unable to obtain file status

Linux Error: 2: No such file or directory

Additional information: 3

这就是因为缺少了36号归档日志的原因，那么现在怎么处理呢？

解决办法：

RMAN> crosscheck archivelog all;

或者：RMAN> change archivelog all crosscheck;

再次执行备份操作即可。

然后需要在RMAN中进行清除操作：

RMAN> list archivelog all;

List of Archived Log Copies
Key Thrd Seq S Low Time Name
------- ---- ------- - --------- ----
62 1 36 X 16-MAY-11 /u01/backup/arch2/1_36_750725106.dbf
61 1 36 X 16-MAY-11 /u01/backup/arch1/1_36_750725106.dbf

RMAN> delete archivelog 61,62;

released channel: ORA_DISK_1
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=141 devtype=DISK

List of Archived Log Copies
Key Thrd Seq S Low Time Name
------- ---- ------- - --------- ----
61 1 36 X 16-MAY-11 /u01/backup/arch1/1_36_750725106.dbf
62 1 36 X 16-MAY-11 /u01/backup/arch2/1_36_750725106.dbf

Do you really want to delete the above objects (enter YES or NO)? y
deleted archive log
archive log filename=/u01/backup/arch1/1_36_750725106.dbf recid=61 stamp=751258131
deleted archive log
archive log filename=/u01/backup/arch2/1_36_750725106.dbf recid=62 stamp=751258131
Deleted 2 objects