[20190515]热备份模式与rman冲突.txt
--//别人的系统做dg时打开热备份模式，忘记关闭，做rman备份时报错。做一个记录。
--//实际上也怪自己，实施时没有讲清楚。通过例子说明：
1.环境：
SCOTT@book> @ ver1
PORT_STRING VERSION BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx 11.2.0.4.0 Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
SYS@book> alter database begin backup;
Database altered.
--//实际上这样做dg，如果数据库不大，对于文件系统的数据库还是很快的，特别目录结构一样的情况。
--//为了避免输入口令，最好先做ssh相互认证。
--//cd /mnt/ramdisk/book
--//ls -1 *.dbf| xargs -I{} -P 4 scp {} oracle@192.168.100.40:/mnt/ramdisk/book
--//或者
--//scp -r /mnt/ramdisk/book/*.dbf oracle@192.168.100.40:/mnt/ramdisk/book/
2.主库做rman备份：
SYS@book> select * from v$backup;
FILE# STATUS CHANGE# TIME
----- ------ ----------- -------------------
1 ACTIVE 15677701496 2019-05-21 08:40:13
2 ACTIVE 15677701496 2019-05-21 08:40:13
3 ACTIVE 15677701496 2019-05-21 08:40:13
4 ACTIVE 15677701496 2019-05-21 08:40:13
5 ACTIVE 15677701496 2019-05-21 08:40:13
6 ACTIVE 15677701496 2019-05-21 08:40:13
7 ACTIVE 15677701496 2019-05-21 08:40:13
8 ACTIVE 15677701496 2019-05-21 08:40:13
9 ACTIVE 15677701496 2019-05-21 08:40:13
10 ACTIVE 15677701496 2019-05-21 08:40:13
11 ACTIVE 15677701496 2019-05-21 08:40:13
12 ACTIVE 15677701496 2019-05-21 08:40:13
13 ACTIVE 15677701496 2019-05-21 08:40:13
13 rows selected.
RMAN> backup database format '/home/oracle/backup/book_%U';
Starting backup at 2019-05-21 08:42:53
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=17 device type=DISK
RMAN-06554: WARNING: file 1 is in backup mode
RMAN-06554: WARNING: file 2 is in backup mode
RMAN-06554: WARNING: file 3 is in backup mode
RMAN-06554: WARNING: file 4 is in backup mode
RMAN-06554: WARNING: file 5 is in backup mode
RMAN-06554: WARNING: file 6 is in backup mode
RMAN-06554: WARNING: file 7 is in backup mode
RMAN-06554: WARNING: file 8 is in backup mode
RMAN-06554: WARNING: file 9 is in backup mode
RMAN-06554: WARNING: file 10 is in backup mode
RMAN-06554: WARNING: file 11 is in backup mode
RMAN-06554: WARNING: file 12 is in backup mode
RMAN-06554: WARNING: file 13 is in backup mode
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00002 name=/mnt/ramdisk/book/sysaux01.dbf
input datafile file number=00003 name=/mnt/ramdisk/book/undotbs01.dbf
input datafile file number=00001 name=/mnt/ramdisk/book/system01.dbf
input datafile file number=00005 name=/mnt/ramdisk/book/example01.dbf
input datafile file number=00004 name=/mnt/ramdisk/book/users01.dbf
input datafile file number=00007 name=/mnt/ramdisk/book/undotbs02.dbf
input datafile file number=00008 name=/mnt/ramdisk/book/undotbs03.dbf
input datafile file number=00006 name=/mnt/ramdisk/book/tea01.dbf
input datafile file number=00009 name=/mnt/ramdisk/book/T01.dbf
input datafile file number=00010 name=/mnt/ramdisk/book/T02.dbf
input datafile file number=00011 name=/mnt/ramdisk/book/T03.dbf
input datafile file number=00012 name=/mnt/ramdisk/book/T04.dbf
input datafile file number=00013 name=/mnt/ramdisk/book/T05.dbf
channel ORA_DISK_1: starting piece 1 at 2019-05-21 08:42:53
channel ORA_DISK_1: finished piece 1 at 2019-05-21 08:43:08
piece handle=/home/oracle/backup/book_2pu2394d_1_1 tag=TAG20190521T084253 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:15
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
including current control file in backup set
including current SPFILE in backup set
channel ORA_DISK_1: starting piece 1 at 2019-05-21 08:43:09
channel ORA_DISK_1: finished piece 1 at 2019-05-21 08:43:11
piece handle=/home/oracle/backup/book_2qu2394s_1_1 tag=TAG20190521T084253 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:02
Finished backup at 2019-05-21 08:43:11
--//注:实际上也备份成功了,不过最好不要这样.
$ ls -l /home/oracle/backup/book_2pu2394d_1_1
-rw-r----- 1 oracle oinstall 2380603392 2019-05-21 08:42:59 /home/oracle/backup/book_2pu2394d_1_1
3.解决很简单，关闭热备份模式就ok了：
SYS@book> alter database end backup;
Database altered.
SYS@book> select * from v$backup;
FILE# STATUS CHANGE# TIME
------------ ------------------ ------------ -------------------
1 NOT ACTIVE 15677701496 2019-05-21 08:40:13
2 NOT ACTIVE 15677701496 2019-05-21 08:40:13
3 NOT ACTIVE 15677701496 2019-05-21 08:40:13
4 NOT ACTIVE 15677701496 2019-05-21 08:40:13
5 NOT ACTIVE 15677701496 2019-05-21 08:40:13
6 NOT ACTIVE 15677701496 2019-05-21 08:40:13
7 NOT ACTIVE 15677701496 2019-05-21 08:40:13
8 NOT ACTIVE 15677701496 2019-05-21 08:40:13
9 NOT ACTIVE 15677701496 2019-05-21 08:40:13
10 NOT ACTIVE 15677701496 2019-05-21 08:40:13
11 NOT ACTIVE 15677701496 2019-05-21 08:40:13
12 NOT ACTIVE 15677701496 2019-05-21 08:40:13
13 NOT ACTIVE 15677701496 2019-05-21 08:40:13
4.另外的问题:
--//实际上打开热备份并不是"冻结"文件头,仅仅冻结scn.实际上你如果发alter system checkpoint;还是会更新文件头的.
--//并且oracle实际上恢复从这个scn(alter system checkpoint命令的)开始恢复:
--//可以参考链接:http://blog.itpub.net/267265/viewspace-2152909/=>[20180413]热备模式相关问题2.txt
SYS@book> alter tablespace users begin backup ;
Tablespace altered.
SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE# , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name FROM v$datafile_header where file# in (1,4);
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME CREATION_CHANGE# RESETLOGS_CHANGE# STATUS CHECKPOINT_COUNT FUZ NAME TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- ------------------------------ ---------------
1 15677702312 2019-05-21 08:47:46 7 925702 ONLINE 13491 YES /mnt/ramdisk/book/system01.dbf SYSTEM
4 15677702482 2019-05-21 08:50:00 16143 925702 ONLINE 13491 YES /mnt/ramdisk/book/users01.dbf USERS
--//CHECKPOINT_CHANGE#发生变化.
SYS@book> alter system checkpoint ;
System altered.
SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE# , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name FROM v$datafile_header where file# in (1,4);
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME CREATION_CHANGE# RESETLOGS_CHANGE# STATUS CHECKPOINT_COUNT FUZ NAME TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- ------------------------------ ---------------
1 15677702587 2019-05-21 08:51:37 7 925702 ONLINE 13492 YES /mnt/ramdisk/book/system01.dbf SYSTEM
4 15677702482 2019-05-21 08:50:00 16143 925702 ONLINE 13492 YES /mnt/ramdisk/book/users01.dbf USERS
--//file#=1的 CHECKPOINT_CHANGE#发生变化,但是file#=4的CHECKPOINT_CHANGE#没有变化.CHECKPOINT_COUNT也是增加的.
select 15677702587,trunc(15677702587/power(2,32)) scn_wrap,mod(15677702587,power(2,32)) scn_base from dual
15677702587 SCN_WRAP SCN_BASE SCN_WRAP16 SCN_BASE16
------------ ------------ ------------ ---------- ----------
15677702587 3 2792800699 3 a676c1bb
select 15677702482,trunc(15677702482/power(2,32)) scn_wrap,mod(15677702482,power(2,32)) scn_base from dual
15677702482 SCN_WRAP SCN_BASE SCN_WRAP16 SCN_BASE16
------------ ------------ ------------ ---------- ----------
15677702482 3 2792800594 3 a676c152
BBED> p /d dba 4,1 kcvfh.kcvfhbcp.kcvcpscn
struct kcvcpscn, 8 bytes @152
ub4 kscnbas @152 2792800699
ub2 kscnwrp @156 3
--//发出alter system checkpoint时在热备分模式要更新这里的信息.
BBED> p /d dba 4,1 kcvfh.kcvfhckp.kcvcpscn
struct kcvcpscn, 8 bytes @484
ub4 kscnbas @484 2792800594
ub2 kscnwrp @488 3
--//文件头scn
SYS@book> alter system checkpoint ;
System altered.
SYS@book> SELECT file#, CHECKPOINT_CHANGE#, CHECKPOINT_TIME,CREATION_CHANGE# , RESETLOGS_CHANGE#,status, CHECKPOINT_COUNT,fuzzy,name,tablespace_name FROM v$datafile_header where file# in (1,4);
FILE# CHECKPOINT_CHANGE# CHECKPOINT_TIME CREATION_CHANGE# RESETLOGS_CHANGE# STATUS CHECKPOINT_COUNT FUZ NAME TABLESPACE_NAME
----- ------------------ ------------------- ---------------- ----------------- ------- ---------------- --- ------------------------------ ---------------
1 15677703057 2019-05-21 08:58:26 7 925702 ONLINE 13493 YES /mnt/ramdisk/book/system01.dbf SYSTEM
4 15677702482 2019-05-21 08:50:00 16143 925702 ONLINE 13493 YES /mnt/ramdisk/book/users01.dbf USERS
BBED> p /d dba 4,1 kcvfh.kcvfhbcp.kcvcpscn
struct kcvcpscn, 8 bytes @152
ub4 kscnbas @152 2792801169
ub2 kscnwrp @156 3
BBED> p /d dba 4,1 kcvfh.kcvfhckp.kcvcpscn
struct kcvcpscn, 8 bytes @484
ub4 kscnbas @484 2792800594
ub2 kscnwrp @488 3
select 15677703057,trunc(15677703057/power(2,32)) scn_wrap,mod(15677703057,power(2,32)) scn_base from dual
15677703057 SCN_WRAP SCN_BASE SCN_WRAP16 SCN_BASE16
------------ ------------ ------------ ---------- ----------
15677703057 3 2792801169 3 a676c391
--//kcvfh.kcvfhbcp.kcvcpscn的信息发生了变化.这样恢复实际上从2792801169开始恢复需要读取的归档大大减少.