[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.