RMAN备份策略与异机恢复一例（续篇）

本文是《RMAN备份策略与异机恢复一例》的续篇，继续实验验证，最终实现两个需求：

• 1.异机恢复临时测试的小库
• 2.传输归档时，实现增量传输

1.异机恢复临时测试的小库

之前异机恢复的需求已经演练成功，现在需要保持之前恢复的库orcl不动，全新恢复一个用于临时测试指定时间点的小库，实例名称规划为testdb。
**注意：**风险点在于一定要注意所有步骤操作仔细，不能影响到现有环境orcl。
**知识点：**
- a.如何恢复指定时间点的数据库
- b.如何重定向数据库各文件的路径
- c.如何验证数据是否是自己需要的

查询数据库全备有两个日期的，一个是2018-06-19的全备，一个是2018-06-21的全备。

RMAN> list backup of database summary;
List of Backups
===============
Key     TY LV S Device Type Completion Time #Pieces #Copies Compressed Tag
------- -- -- - ----------- --------------- ------- ------- ---------- ---
45      B  F  A DISK        21-JUN-18       1       1       YES        TAG20180621T073703
46      B  F  A DISK        19-JUN-18       1       1       YES        TAG20180619T170003
54      B  F  A DISK        21-JUN-18       1       1       YES        TAG20180621T073703
58      B  F  A DISK        21-JUN-18       1       1       YES        TAG20180621T073703
60      B  F  A DISK        21-JUN-18       1       1       YES        TAG20180621T073703

若直接restore database，默认会从最新的全备转储恢复，那如何可以用到之前的全备？

RMAN> sql "alter session set nls_date_format=''yyyy-mm-dd hh24:mi:ss''";
sql statement: alter session set nls_date_format=''yyyy-mm-dd hh24:mi:ss''
RMAN> restore database until time '2018-06-20 18:00:00' validate;
Starting restore at 21-JUN-18
using channel ORA_DISK_1
using channel ORA_DISK_2
using channel ORA_DISK_3
using channel ORA_DISK_4
using channel ORA_DISK_5
using channel ORA_DISK_6
channel ORA_DISK_1: starting validation of datafile backup set
channel ORA_DISK_1: reading from backup piece /tmp/FULLBAK_ORCL_20180619_18_1.DBFILE
channel ORA_DISK_1: piece handle=/tmp/FULLBAK_ORCL_20180619_18_1.DBFILE tag=TAG20180619T170003
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: validation complete, elapsed time: 00:00:45
Finished restore at 21-JUN-18
RMAN>

可以看到只要指定了合适的until time参数，就自动会从之前合适的备份集中转储（这里实验就是20180619了）。

现在来恢复小库到2018-06-20 18:00:00这个时间点，实例名为testdb：

[oracle@jystdrac1 ~]$ export ORACLE_SID=testdb
[oracle@jystdrac1 ~]$ echo $ORACLE_SID
testdb
[oracle@jystdrac1 ~]$ mkdir -p /u01/oradata/testdb

参数文件，适当减少内存参数，增加db_unique_name参数：

[oracle@jystdrac1 tmp]$ strings ORCL.46.1.20180621.SPFILE
[oracle@jystdrac1 testdb]$ vi pfile.ora
*.audit_file_dest='/u01/app/oracle/admin/testdb/adump'
*.audit_trail='db'
*.compatible='11.2.0.4.0'
*.control_files='/u01/oradata/testdb/control01.ctl','/u01/oradata/testdb/control02.ctl'
*.db_block_size=8192
*.db_domain=''
*.db_name='orcl'
*.db_unique_name='testdb'
*.diagnostic_dest='/u01/app/oracle'
*.dispatchers='(PROTOCOL=TCP) (SERVICE=testdbXDB)'
*.log_archive_dest_1='LOCATION=/u01/arch'
*.memory_target=334173952
*.open_cursors=300
*.processes=150
*.remote_login_passwordfile='EXCLUSIVE'
*.undo_tablespace='UNDOTBS1'
[oracle@jystdrac1 testdb]$ mkdir -p /u01/app/oracle/admin/testdb/adump

启动到nomount：

SQL> startup nomount pfile='/u01/oradata/testdb/pfile.ora';

恢复控制文件：

[oracle@jystdrac1 tmp]$ rman target /
RMAN> restore controlfile from '/tmp/ORCL.45.1.20180621.CTL';
RMAN> alter database mount;
select name from v$datafile union all
select name from v$tempfile union all
select member from v$logfile;
NAME
------------------------------------------------------
/u01/oradata/orcl/system01.dbf
/u01/oradata/orcl/sysaux01.dbf
/u01/oradata/orcl/undotbs01.dbf
/u01/oradata/orcl/users01.dbf
/u01/oradata/orcl/temp01.dbf
/u01/oradata/orcl/redo03.log
/u01/oradata/orcl/redo02.log
/u01/oradata/orcl/redo01.log
8 rows selected.
set linesize 140 pagesize 100
select 'alter database rename file '''||name||''' to '''||name||''';' from v$tempfile union all
select 'alter database rename file '''||member||''' to '''||member||''';' from v$logfile;
替换规则：`to '/u01/oradata/orcl` => to `'/u01/oradata/testdb`
alter database rename file '/u01/oradata/orcl/temp01.dbf' to '/u01/oradata/testdb/temp01.dbf';
alter database rename file '/u01/oradata/orcl/redo03.log' to '/u01/oradata/testdb/redo03.log';
alter database rename file '/u01/oradata/orcl/redo02.log' to '/u01/oradata/testdb/redo02.log';
alter database rename file '/u01/oradata/orcl/redo01.log' to '/u01/oradata/testdb/redo01.log';
--注意如果这里尝试rename数据文件，由于指定的数据文件还不存在，是会报错的，类似这样的错误：
SQL> alter database rename file '/u01/oradata/orcl/sysaux01.dbf' to '/u01/oradata/testdb/sysaux01.dbf'
*
ERROR at line 1:
ORA-01511: error in renaming log/data files
ORA-01141: error renaming data file 2 - new file '/u01/oradata/testdb/sysaux01.dbf' not found
ORA-01110: data file 2: '/u01/oradata/orcl/sysaux01.dbf'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3

检查备份和归档：

crosscheck backup;
crosscheck archivelog all;
delete noprompt expired backup;
delete noprompt expired archivelog all;
catalog start with '/tmp/';
crosscheck backup;

重定向数据文件-方法1：

run {
set newname for datafile '/u01/oradata/orcl/system01.dbf' to '/u01/oradata/testdb/system01.dbf';
set newname for datafile '/u01/oradata/orcl/sysaux01.dbf' to '/u01/oradata/testdb/sysaux01.dbf';
set newname for datafile '/u01/oradata/orcl/undotbs01.dbf' to '/u01/oradata/testdb/undotbs01.dbf';
set newname for datafile '/u01/oradata/orcl/users01.dbf' to '/u01/oradata/testdb/users01.dbf';
sql "alter session set nls_date_format=''yyyy-mm-dd hh24:mi:ss''";
set until time '2018-06-20 18:00:00';
restore database;
switch datafile all;
}
RMAN> recover database until time '2018-06-20 18:00:00';

重定向数据文件-方法2：

--这里语法要求一定要指定%f或者%U，通常选择%U更易识别一些，这里测试使用%f只有文件号，不够友好。
run {
set newname for database to '/u01/oradata/testdb/%f';
sql "alter session set nls_date_format=''yyyy-mm-dd hh24:mi:ss''";
set until time '2018-06-20 18:00:00';
restore database;
switch datafile all;
}
RMAN> recover database until time '2018-06-20 18:00:00';

此时一定要重新确认下临时文件和redo日志文件的位置，如果没有更改正确，务必改正，否则会造成灾难性后果!!!

SQL> select name from v$datafile union all
  2  select name from v$tempfile union all
  3  select member from v$logfile;
NAME
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
/u01/oradata/testdb/1
/u01/oradata/testdb/2
/u01/oradata/testdb/3
/u01/oradata/testdb/4
/u01/oradata/orcl/temp01.dbf
/u01/oradata/orcl/redo03.log
/u01/oradata/orcl/redo02.log
/u01/oradata/orcl/redo01.log
8 rows selected.
--如果不对，需要rename修改，然后再次查询确认：
alter database rename file '/u01/oradata/orcl/temp01.dbf' to '/u01/oradata/testdb/temp01.dbf';
alter database rename file '/u01/oradata/orcl/redo03.log' to '/u01/oradata/testdb/redo03.log';
alter database rename file '/u01/oradata/orcl/redo02.log' to '/u01/oradata/testdb/redo02.log';
alter database rename file '/u01/oradata/orcl/redo01.log' to '/u01/oradata/testdb/redo01.log';

汇总一下本节开头提出的问题：

a.如何恢复指定时间点的数据库

	RMAN>
	sql "alter session set nls_date_format=''yyyy-mm-dd hh24:mi:ss''";
	restore database until time '2018-06-20 18:00:00';
	recover database until time '2018-06-20 18:00:00';

b.如何重定向数据库各文件的路径

	--方法1：
	RMAN>
	run {
	set newname for datafile '/u01/oradata/orcl/system01.dbf' to '/u01/oradata/testdb/system01.dbf';
	restore...
	switch datafile all;
	}
	--方法2：
	RMAN>
	run {
	set newname for database to '/u01/oradata/testdb/';
	restore...
	switch database to copy;
	}
	--注意：已经反复强调过多次，在open resetlogs前都需要检查文件位置是否正确，尤其是redo文件的位置！这里需要将redo和temp文件都重定向到新的目录下：
	alter database rename file '/u01/oradata/orcl/temp01.dbf' to '/u01/oradata/testdb/temp01.dbf';
	alter database rename file '/u01/oradata/orcl/redo03.log' to '/u01/oradata/testdb/redo03.log';
	alter database rename file '/u01/oradata/orcl/redo02.log' to '/u01/oradata/testdb/redo02.log';
	alter database rename file '/u01/oradata/orcl/redo01.log' to '/u01/oradata/testdb/redo01.log';

c.如何验证数据是否是自己需要的

	SQL> alter database open read only;
	Check Your DATA...
	SQL> shutdown abort;
	SQL> startup mount;
	SQL> alter database open resetlogs;

2.传输归档时，实现增量传输

之前传输归档时，当天内的文件是scp直接传输的，现在需要实现增量传输。

知识点：

• a.如何在Linux实现增量传输文件的功能

之前windows是通过 xcopy /y /d来实现这个需求的：

/y

禁止提示确认要覆盖已存在的目标文件。

/d [:MM-DD-YYYY]

只复制那些在指定日期或指定日期之后更改过的源文件。如果不包括“MM-DD-YYYY”值，“xcopy”会复制比现有“Destination”文件新的所有“Source”文件。该命令行选项使您可以更新更改过的文件。

实际测试将之前的scp复制部分替换成rsync --ignore-existing，之前的scp部分注释掉，添加rsync部分：

--全备脚本：
#echo "Begin scp at : `date`" >>${1}/backup_full.log
#scp ${1}/*`date +%Y%m%d`* oracle@192.168.1.61:/tmp/
#echo "End scp at : `date`" >>${1}/backup_full.log
echo "Begin rsync at : `date`" >>${1}/backup_full.log
rsync --ignore-existing ${1}/*`date +%Y%m%d`* oracle@192.168.1.61:/u01/orabak/
echo "End rsync at : `date`" >>${1}/backup_full.log
--归档备份脚本：
#echo "Begin scp at : `date`" >>${1}/backup_arch.log
#scp ${1}/*`date +%Y%m%d`*.{CTL,SPFILE,ARC} oracle@192.168.1.61:/tmp/
#echo "End scp at : `date`" >>${1}/backup_arch.log
echo "Begin rsync at : `date`" >>${1}/backup_arch.log
rsync --ignore-existing ${1}/*`date +%Y%m%d`*.{CTL,SPFILE,ARC} oracle@192.168.1.61:/u01/orabak/
echo "End rsync at : `date`" >>${1}/backup_arch.log

测试，定时任务调整为每个小时在整点时备份归档：

[ora11204@OEL-ASM orabak]$ crontab -l
0 1 * * * /u01/orabak/scripts/backup.sh /u01/orabak
0 * * * * /u01/orabak/scripts/backuparch.sh /u01/orabak

去异机192.168.1.61去观察已经传输过来的文件修改时间，确认每小时确实只复制传输那些新文件：

-rw-r----- 1 oracle oinstall 9.5M Jun 21 13:00 ORCL.79.1.20180621.CTL
-rw-r----- 1 oracle oinstall  96K Jun 21 13:00 ORCL.80.1.20180621.SPFILE
-rw-r----- 1 oracle oinstall 2.5K Jun 21 13:00 ORCL.82.1.20180621.ARC
-rw-r----- 1 oracle oinstall  15K Jun 21 13:00 ORCL.81.1.20180621.ARC
-rw-r----- 1 oracle oinstall 9.5M Jun 21 14:00 ORCL.83.1.20180621.CTL
-rw-r----- 1 oracle oinstall  96K Jun 21 14:00 ORCL.84.1.20180621.SPFILE
-rw-r----- 1 oracle oinstall 2.5K Jun 21 14:00 ORCL.86.1.20180621.ARC
-rw-r----- 1 oracle oinstall 1.2M Jun 21 14:00 ORCL.85.1.20180621.ARC
-rw-r----- 1 oracle oinstall 9.5M Jun 21 15:00 ORCL.87.1.20180621.CTL
-rw-r----- 1 oracle oinstall  96K Jun 21 15:00 ORCL.88.1.20180621.SPFILE
-rw-r----- 1 oracle oinstall 2.5K Jun 21 15:00 ORCL.90.1.20180621.ARC
-rw-r----- 1 oracle oinstall 1.2M Jun 21 15:00 ORCL.89.1.20180621.ARC
-rw-r----- 1 oracle oinstall 9.5M Jun 21 16:00 ORCL.91.1.20180621.CTL
-rw-r----- 1 oracle oinstall  96K Jun 21 16:00 ORCL.92.1.20180621.SPFILE
-rw-r----- 1 oracle oinstall 2.5K Jun 21 16:00 ORCL.94.1.20180621.ARC
-rw-r----- 1 oracle oinstall 1.2M Jun 21 16:00 ORCL.93.1.20180621.ARC

最终考虑到一些特殊情况，比如有些文件同步一半突然断电，所以更偏向于使用rsync -t -v同步满足需求,这样也更加匹配之前windows的xcopy /y /d方式。

至此，通过rsync命令实现了增量传输文件的需求。