ORACLE RAC資料庫的備份與恢復(3)

3、執行RAC資料庫的備份

　　基本上，RAC下建立備份任務，備份語句是不需要做什麼修改的，只要前面的準備工作都做好了(主要是歸檔檔案)，那麼備份是會很順暢的。

　　首先來舉個例子，預設情況下直接執行備份，通過RMAN連線到任意結點執行，這裡我們在節點2端執行備份操作：

[oracle@jssdbn 2 ~]$ rman target /

Recovery Manager: Release 10.2.0.4.0 - Production on T hu Jan 2 11: 1 4:19 2010

connected to target database: JSSDB (DBID=953576437)

RMAN> run{

2> allocate channel c0 device type disk format ¨/data/%U¨;

3> backup database plus archivelog ;

4> }

allocated channel: c0

channel c0: sid=146 instance=jssdbn2 devtype=DISK

.............................

RMAN-03002: failure of backup plus archivelog command at 01/28/2010 11:17:07

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

ORA-19625: error identifying file /data/oradata/jssdbn1/archivelog/1_214_703671669.dbf

ORA-27037: unable to obtain file status

Linux-x86_64 Error: 2: No such file or directory

　　從提示資訊可以清晰的看出，錯誤的原因是找不到指定的歸檔檔案。實際上這裡的缺少不是沒有，而是說執行備份的節點上找不到這個歸檔，遇到這種問題，就可以按照1.2小節中提示的方法進行處理。

　　問題處理完之後，再次執行相同的備份指令碼：

RMAN> run{

2> allocate channel c0 device type disk format ¨/data/backup/%U¨;

3> backup database plus archivelog ;

4> }

using target database control file instead of recovery catalog

allocated channel: c0

channel c0: sid=147 instance=jssdbn2 devtype=DISK

Starting backup at 28-JAN-10

current log archived

archived log /data/oradata/jssdbn1/archivelog/1_214_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 214

archived log /data/oradata/jssdbn1/archivelog/1_215_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 215

archived log /data/oradata/jssdbn1/archivelog/1_216_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 216

archived log /data/oradata/jssdbn1/archivelog/1_217_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 217

archived log /data/oradata/jssdbn1/archivelog/1_218_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 218

archived log /data/oradata/jssdbn1/archivelog/1_219_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 219

archived log /data/oradata/jssdbn1/archivelog/1_220_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 220

archived log /data/oradata/jssdbn1/archivelog/1_221_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 221

archived log /data/oradata/jssdbn1/archivelog/1_222_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 222

archived log /data/oradata/jssdbn1/archivelog/2_80_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 2, sequence 80

channel c0: starting archive log backupset

channel c0: specifying archive log(s) in backup set

input archive log thread=1 sequence=214 recid=15 stamp=709470986

input archive log thread=1 sequence=215 recid=16 stamp=709470986

input archive log thread=1 sequence=216 recid=17 stamp=709470986

input archive log thread=1 sequence=217 recid=18 stamp=709470986

input archive log thread=1 sequence=218 recid=10 stamp=709386699

input archive log thread=1 sequence=219 recid=8 stamp=709377003

input archive log thread=1 sequence=220 recid=13 stamp=709470839

input archive log thread=1 sequence=221 recid=20 stamp=709471027

input archive log thread=1 sequence=222 recid=24 stamp=709471178

input archive log thread=2 sequence=80 recid=22 stamp=709471126

input archive log thread=2 sequence=81 recid=6 stamp=709351223

input archive log thread=2 sequence=82 recid=11 stamp=709423258

input archive log thread=2 sequence=83 recid=12 stamp=709470834

input archive log thread=2 sequence=84 recid=19 stamp=709471026

input archive log thread=2 sequence=85 recid=23 stamp=709471176

channel c0: starting piece 1 at 28-JAN-10

channel c0: finished piece 1 at 28-JAN-10

piece handle=/data/backup/01l4jaui_1_1 tag=TAG20100128T111946 comment=NONE

channel c0: backup set complete, elapsed time: 00:00:16

Finished backup at 28-JAN-10

Starting backup at 28-JAN-10

channel c0: starting full datafile backupset

channel c0: specifying datafile(s) in backupset

input datafile fno=00003 name=+ASMDISK1/jssdb/datafile/sysaux.266.703671697

input datafile fno=00001 name=+ASMDISK1/jssdb/datafile/system.260.703671683

input datafile fno=00002 name=+ASMDISK1/jssdb/datafile/undotbs1.259.703671695

input datafile fno=00004 name=+ASMDISK1/jssdb/datafile/undotbs2.258.703671705

input datafile fno=00006 name=+ASMDISK1/jssdb/datafile/jsstbs.269.703779631

input datafile fno=00005 name=+ASMDISK1/jssdb/datafile/users.257.703671709

channel c0: starting piece 1 at 28-JAN-10

channel c0: finished piece 1 at 28-JAN-10

piece handle=/data/backup/02l4jav5_1_1 tag=TAG20100128T112005 comment=NONE

channel c0: backup set complete, elapsed time: 00:00:25

channel c0: starting full datafile backupset

channel c0: specifying datafile(s) in backupset

including current control file in backupset

including current SPFILE in backupset

channel c0: starting piece 1 at 28-JAN-10

channel c0: finished piece 1 at 28-JAN-10

piece handle=/data/backup/03l4javu_1_1 tag=TAG20100128T112005 comment=NONE

channel c0: backup set complete, elapsed time: 00:00:03

Finished backup at 28-JAN-10

Starting backup at 28-JAN-10

current log archived

archived log /data/oradata/jssdbn1/archivelog/1_223_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 223

channel c0: starting archive log backupset

channel c0: specifying archive log(s) in backup set

input archive log thread=1 sequence=223 recid=26 stamp=709471235

input archive log thread=2 sequence=86 recid=28 stamp=709471236

channel c0: starting piece 1 at 28-JAN-10

channel c0: finished piece 1 at 28-JAN-10

piece handle=/data/backup/04l4jb05_1_1 tag=TAG20100128T112037 comment=NONE

channel c0: backup set complete, elapsed time: 00:00:02

Finished backup at 28-JAN-10

　　一切順利，備份集建立成功。

　　不過，這裡隱含一個問題，通常我們習慣於在備份完歸檔之後刪除原歸檔檔案，以釋放相應的磁碟空間，不過在當前這個情況下，如果你嘗試清除歸檔的話，如無意外肯定會報錯，例如：

RMAN> delete archivelog sequence 214 thread 1;

allocated channel: ORA_DISK_1

channel ORA_DISK_1: sid=134 instance=jssdbn2 devtype=DISK

List of Archived Log Copies

Key Thrd Seq S Low Time Name

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

15 1 214 A 24-JAN-10 /data/oradata/jssdbn2/archivelog/1_214_703671669.dbf

1 1 214 A 24-JAN-10 /data/oradata/jssdbn1/archivelog/1_214_703671669.dbf

Do you really want to delete the above objects (enter YES or NO)? yes

deleted archive log

archive log filename=/data/oradata/jssdbn2/archivelog/1_214_703671669.dbf recid=15 stamp=709470986

Deleted 1 objects

RMAN-06207: WARNING: 1 objects could not be deleted for DISK channel(s) due

RMAN-06208: to mismatched status. Use CROSSCHECK command to fix status

RMAN-06210: List of Mismatched objects

RMAN-06211: ==========================

RMAN-06212: Object Type Filename/Handle

RMAN-06213: --------------- ---------------------------------------------------

　　節點2端的歸檔成功刪除，可是節點1端生成的歸檔刪除報錯，覺著奇怪嗎？其實如果你稍稍開動一下腦筋，隨便動用幾十萬億個腦細胞就肯定能想明白這個事兒，沒錯，這裡報錯的原來就是節點2上操作不了節點1中的" /data/oradata/jssdbn1/archivelog/1_214_703671669.dbf " 這個檔案，你想說到節點1端去刪除？那也會有問題，因為節點1又操作不了節點2上的" /data/oradata/jssdbn2/archivelog/1_214_703671669.dbf " 這個檔案，咋整？我有辦法，用家樂濃湯寶吧，三碗水，一個雞湯口味。。。。Oo對不起對不起，最近廣告看多了。我真正想說的是，用RMAN中的通道吧。

插播內容：配置多通道連線不同例項，認真看，不是廣告。

　　可以通過configure預配置幾個通道(一般有幾個例項就配幾個通道)，用來連線相應的例項，命令列如下：

RMAN> configure channel 1 device type disk connect ¨sys/123456@jssdbn1¨;

new RMAN configuration parameters:

CONFIGURE CHANNEL 1 DEVICE TYPE DISK CONNECT ¨*¨;

new RMAN configuration parameters are successfully stored

released channel: ORA_DISK_1

RMAN> configure channel 2 device type disk connect ¨sys/123456@jssdbn2¨;

new RMAN configuration parameters:

CONFIGURE CHANNEL 2 DEVICE TYPE DISK CONNECT ¨*¨;

　　Configure channel 大家應該看著眼熟，有不認識的建議重溫" 一步一步學RMAN" ，或者瀏覽" 塗抹ORACLE--三思筆記第8章" ，關於connect子句簡單解釋兩句，後跟目標例項的使用者名稱密碼及網路服務名，這個網路服務名要確保執行備份的節點中確實進行了配置喲，不然該通道連線時肯定就會報錯了。

　　配置完成之後，檢視當前通道配置情況，應顯示如下：

RMAN> show channel;

RMAN configuration parameters are:

CONFIGURE CHANNEL 1 DEVICE TYPE DISK CONNECT ¨*¨;

　　而且這種方式還有一個好處，就是RMAN能夠智慧的對備份中出現"問題"的任務進行再分配，比如說通道1和通道2同時執行備份，其中通道1備份資料檔案134，通道2備份資料檔案2和5，假如通道2執行過程中由於某些原因崩潰，RMAN可以自動將任務放回到通道1上執行。

　　接下來，還有很重要的一步，啟動並行，並且至少要啟動"節點數量"個並行度。這樣的目的是為了RMAN在分配任務時，自動至少啟動多個通道並連線到相應的例項上，操作如下，例如我們這裡的雙節點RAC，就配置2個並行度：

RMAN> configure device type disk parallelism 2;

new RMAN configuration parameters:

CONFIGURE DEVICE TYPE DISK PARALLELISM 2 BACKUP TYPE TO BACKUPSET;

new RMAN configuration parameters are successfully stored

　　這樣，當執行RMAN任務時，它就會根據任務所需，自動分配通道連線到適當例項，執行適當的操作。例如，再將從節點2端刪除214序號的歸檔檔案，操作如下：

RMAN> delete archivelog sequence 214;

allocated channel: ORA_DISK_1

channel ORA_DISK_1: sid=130 instance=jssdbn1 devtype=DISK

allocated channel: ORA_DISK_2

channel ORA_DISK_2: sid=152 instance=jssdbn2 devtype=DISK

List of Archived Log Copies

Key Thrd Seq S Low Time Name

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

1 1 214 A 24-JAN-10 /data/oradata/jssdbn1/archivelog/1_214_703671669.dbf

Do you really want to delete the above objects (enter YES or NO)? yes

deleted archive log

archive log filename=/data/oradata/jssdbn1/archivelog/1_214_703671669.dbf recid=1 stamp=709219728

　　成功刪除，這個成功也體現了分配通道後RMAN的智慧，它會根據配置給不同的通道分配不同的任務，這樣也就不用擔心節點路徑不同導致刪除任務的失敗了。

　　路障基本掃除，下面綜合來測試一下，執行指令碼如下：

RMAN> run{

allocate channel c0 device type disk format ¨/data/backup/%U¨;

backup database plus archivelog;

release channel c0;

}

allocated channel: c0

channel c0: sid=144 instance=jssdbn2 devtype=DISK

Starting backup at 03-FEB-10

current log archived

archived log /data/oradata/jssdbn1/archivelog/1_224_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 224

archived log /data/oradata/jssdbn1/archivelog/1_225_703671669.dbf not found or out of sync with catalog

.....................

........................

trying alternate file for archivelog thread 1, sequence 237

archived log /data/oradata/jssdbn1/archivelog/2_88_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 2, sequence 88

channel c0: starting archive log backupset

channel c0: specifying archive log(s) in backup set

input archive log thread=1 sequence=224 recid=64 stamp=709997627

input archive log thread=1 sequence=225 recid=65 stamp=709997630

............................

...............................

input archive log thread=2 sequence=97 recid=66 stamp=709997682

channel c0: starting piece 1 at 03-FEB-10

channel c0: finished piece 1 at 03-FEB-10

piece handle=/data/backup/05l53d3s_1_1 tag=TAG20100203T133451 comment=NONE

channel c0: backup set complete, elapsed time: 00:00:36

Finished backup at 03-FEB-10

Starting backup at 03-FEB-10

channel c0: starting full datafile backupset

channel c0: specifying datafile(s) in backupset

input datafile fno=00003 name=+ASMDISK1/jssdb/datafile/sysaux.266.703671697

input datafile fno=00001 name=+ASMDISK1/jssdb/datafile/system.260.703671683

input datafile fno=00002 name=+ASMDISK1/jssdb/datafile/undotbs1.259.703671695

input datafile fno=00004 name=+ASMDISK1/jssdb/datafile/undotbs2.258.703671705

input datafile fno=00006 name=+ASMDISK1/jssdb/datafile/jsstbs.269.703779631

input datafile fno=00005 name=+ASMDISK1/jssdb/datafile/users.257.703671709

channel c0: starting piece 1 at 03-FEB-10

channel c0: finished piece 1 at 03-FEB-10

piece handle=/data/backup/06l53d53_1_1 tag=TAG20100203T133531 comment=NONE

channel c0: backup set complete, elapsed time: 00:00:25

channel c0: starting full datafile backupset

channel c0: specifying datafile(s) in backupset

including current control file in backupset

including current SPFILE in backupset

channel c0: starting piece 1 at 03-FEB-10

channel c0: finished piece 1 at 03-FEB-10

piece handle=/data/backup/07l53d5s_1_1 tag=TAG20100203T133531 comment=NONE

channel c0: backup set complete, elapsed time: 00:00:03

Finished backup at 03-FEB-10

Starting backup at 03-FEB-10

current log archived

archived log /data/oradata/jssdbn1/archivelog/1_238_703671669.dbf not found or out of sync with catalog

trying alternate file for archivelog thread 1, sequence 238

channel c0: starting archive log backupset

channel c0: specifying archive log(s) in backup set

input archive log thread=1 sequence=238 recid=70 stamp=709997762

input archive log thread=2 sequence=98 recid=69 stamp=709997760

channel c0: starting piece 1 at 03-FEB-10

channel c0: finished piece 1 at 03-FEB-10

piece handle=/data/backup/08l53d64_1_1 tag=TAG20100203T133604 comment=NONE

channel c0: backup set complete, elapsed time: 00:00:02

Finished backup at 03-FEB-10

　　然後執行命令刪除所有已備份過的歸檔檔案，因為有預設通道的存在，因此這裡可以不用再分配通道了，直接執行如下：

RMAN> delete noprompt archivelog all backed up 1 times to device type disk;

allocated channel: ORA_DISK_1

channel ORA_DISK_1: sid=127 instance=jssdbn1 devtype=DISK

allocated channel: ORA_DISK_2

channel ORA_DISK_2: sid=128 instance=jssdbn2 devtype=DISK

List of Archived Log Copies

Key Thrd Seq S Low Time Name

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

64 1 224 A 28-JAN-10 /data/oradata/jssdbn2/archivelog/1_224_703671669.dbf

.......................................

.........................................

66 2 97 A 03-FEB-10 /data/oradata/jssdbn2/archivelog/2_97_703671669.dbf

69 2 98 A 03-FEB-10 /data/oradata/jssdbn2/archivelog/2_98_703671669.dbf

deleted archive log

archive log filename=/data/oradata/jssdbn1/archivelog/1_224_703671669.dbf recid=30 stamp=709542410

deleted archive log

archive log filename=/data/oradata/jssdbn1/archivelog/1_225_703671669.dbf recid=32 stamp=709542491

.......................................

.........................................

deleted archive log

archive log filename=/data/oradata/jssdbn2/archivelog/2_97_703671669.dbf recid=66 stamp=709997682

deleted archive log

archive log filename=/data/oradata/jssdbn2/archivelog/2_98_703671669.dbf recid=69 stamp=709997760

　　竣工！其它就不說了，上述執行的指令碼為RMAN備份的最核心指令碼，實際使用時可在此基本上進行相應的補充，比如增加備份型別、通道的設定、驗證備份集、清除過期備份、日誌輸出等等操作。這部分相關知識已有專門論述，在此不再重複，感興趣的朋友可以參考三思的著作“塗抹ORACLE--三思筆記” 一書第七章和第八章。

來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/7607759/viewspace-631030/，如需轉載，請註明出處，否則將追究法律責任。

ORACLE RAC資料庫的備份與恢復(3)

3、執行RAC資料庫的備份

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