本文是《RMAN備份策略與異機恢復一例》的續篇，繼續實驗驗證，最終實現兩個需求：
1.異機恢復臨時測試的小庫
之前異機恢復的需求已經演練成功，現在需要保持之前恢復的庫orcl不動，全新恢復一個用於臨時測試指定時間點的小庫，實例名稱規划為testdb。 **注意：**風險點在於一定要注意所有步驟操作仔細，不能影響到現有環境orcl。 **知識點：** - a.如何恢復指定時間點的數據庫 - b.如何重定向數據庫各文件的路徑 - c.如何驗證數據是否是自己需要的查詢數據庫全備有兩個日期的，一個是2018-06-19的全備，一個是2018-06-21的全備。
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，默認會從最新的全備轉儲恢復，那如何可以用到之前的全備？
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適的until time參數，就自動會從之前合適的備份集中轉儲（這里實驗就是20180619了）。
現在來恢復小庫到2018-06-20 18:00:00這個時間點，實例名為testdb：
[oracle@jystdrac1 ~]$ export ORACLE_SID=testdb
[oracle@jystdrac1 ~]$ echo $ORACLE_SID
testdb
[oracle@jystdrac1 ~]$ mkdir -p /u01/oradata/testdb
參數文件，適當減少內存參數，增加db_unique_name參數：
[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
啟動到nomount：
SQL> startup nomount pfile='/u01/oradata/testdb/pfile.ora';
恢復控制文件：
[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;
替換規則：`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';
--注意如果這里嘗試rename數據文件，由於指定的數據文件還不存在，是會報錯的，類似這樣的錯誤：
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
檢查備份和歸檔：
crosscheck backup;
crosscheck archivelog all;
delete noprompt expired backup;
delete noprompt expired archivelog all;
catalog start with '/tmp/';
crosscheck backup;
重定向數據文件-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';
重定向數據文件-方法2：
--這里語法要求一定要指定%f或者%U，通常選擇%U更易識別一些，這里測試使用%f只有文件號，不夠友好。
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';
此時一定要重新確認下臨時文件和redo日志文件的位置，如果沒有更改正確，務必改正，否則會造成災難性后果!!!
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.
--如果不對，需要rename修改，然后再次查詢確認：
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';
匯總一下本節開頭提出的問題：
a.如何恢復指定時間點的數據庫
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.如何重定向數據庫各文件的路徑
--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：已經反復強調過多次，在open resetlogs前都需要檢查文件位置是否正確，尤其是redo文件的位置！這里需要將redo和temp文件都重定向到新的目錄下：
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.如何驗證數據是否是自己需要的
SQL> alter database open read only;
Check Your DATA...
SQL> shutdown abort;
SQL> startup mount;
SQL> alter database open resetlogs;
2.傳輸歸檔時，實現增量傳輸
之前傳輸歸檔時，當天內的文件是scp直接傳輸的，現在需要實現增量傳輸。知識點：
- a.如何在Linux實現增量傳輸文件的功能
之前windows是通過 xcopy /y /d來實現這個需求的：
/y
禁止提示確認要覆蓋已存在的目標文件。
/d [:MM-DD-YYYY]
只復制那些在指定日期或指定日期之后更改過的源文件。如果不包括“MM-DD-YYYY”值，“xcopy”會復制比現有“Destination”文件新的所有“Source”文件。該命令行選項使您可以更新更改過的文件。
實際測試將之前的scp復制部分替換成rsync --ignore-existing，之前的scp部分注釋掉，添加rsync部分：
--全備腳本：
#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
--歸檔備份腳本：
#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
測試，定時任務調整為每個小時在整點時備份歸檔：
[ora11204@OEL-ASM orabak]$ crontab -l
0 1 * * * /u01/orabak/scripts/backup.sh /u01/orabak
0 * * * * /u01/orabak/scripts/backuparch.sh /u01/orabak
去異機192.168.1.61去觀察已經傳輸過來的文件修改時間，確認每小時確實只復制傳輸那些新文件：
-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
最終考慮到一些特殊情況，比如有些文件同步一半突然斷電，所以更偏向於使用rsync -t -v同步滿足需求,這樣也更加匹配之前windows的xcopy /y /d方式。
至此，通過rsync命令實現了增量傳輸文件的需求。