[20190510]rman备份的疑问8.txt

--//上午测试rman备份多个文件,探究input memory buffer 的问题.--//补充测试5个文件的情况.--//http://blog.itpub.net/267265/viewspace-2148246/=>[20171204]关于rman备份疑问4.txt 1.环境:SCOTT@book> @ ver1PORT_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$ cat dx.sqldrop tablespace t&1 including contents and datafiles;CREATE TABLESPACE T&1 DATAFILE '/mnt/ramdisk/book/T&1..dbf' SIZE 6M AUTOEXTEND OFF LOGGING ONLINE EXTENT MANAGEMENT LOCAL AUTOALLOCATE BLOCKSIZE 8K SEGMENT SPACE MANAGEMENT AUTO FLASHBACK ON;create table t&1 tablespace t&1 as select rownum id ,to_char(rownum,'FM000000')||lpad('&&2',26,'&&2') name from dual connect by level<=1e5;--//T&1..dbf 2个点.事后才发现这个小问题.$ paste -d " " <(seq -f "%02g" 5 ) <((echo A B C D E | tr ' ' '\n' )) | xargs -IQ echo @ dx Q | sqlplus -s -l scott/book2.修改rman配置:RMAN> CONFIGURE CHANNEL 1 DEVICE TYPE DISK RATE 128 K;using target database control file instead of recovery catalogold RMAN configuration parameters:CONFIGURE CHANNEL 1 DEVICE TYPE DISK RATE 512 K;new RMAN configuration parameters:CONFIGURE CHANNEL 1 DEVICE TYPE DISK RATE 128 K;new RMAN configuration parameters are successfully stored--//延迟备份写盘速度,就可以看出一些细节.--//RMAN> CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET;--//RMAN> CONFIGURE CONTROLFILE AUTOBACKUP OFF;3.备份:RMAN> backup  datafile 9,10,11,12,13 format '/home/oracle/backup/t12345_%t_%U' ;Starting backup at 2019-05-10 17:16:28allocated channel: ORA_DISK_1channel ORA_DISK_1: SID=58 device type=DISKchannel ORA_DISK_1: starting full datafile backup setchannel ORA_DISK_1: specifying datafile(s) in backup setinput datafile file number=00009 name=/mnt/ramdisk/book/T01dbfinput datafile file number=00010 name=/mnt/ramdisk/book/T02dbfinput datafile file number=00011 name=/mnt/ramdisk/book/T03dbfinput datafile file number=00012 name=/mnt/ramdisk/book/T04dbfinput datafile file number=00013 name=/mnt/ramdisk/book/T05dbfchannel ORA_DISK_1: starting piece 1 at 2019-05-10 17:16:28channel ORA_DISK_1: finished piece 1 at 2019-05-10 17:20:33piece handle=/home/oracle/backup/t12345_1007918188_2ju1773c_1_1 tag=TAG20190510T171628 comment=NONEchannel ORA_DISK_1: backup set complete, elapsed time: 00:04:05channel ORA_DISK_1: throttle time: 0:04:00Finished backup at 2019-05-10 17:20:33--//执行如下:SELECT set_count        ,device_type        ,TYPE        ,filename        ,buffer_size        ,buffer_count        ,open_time        ,close_time    FROM v$backup_async_io   where set_count=83ORDER BY set_count        ,TYPE        ,open_time        ,close_time;SET_COUNT DEVICE_TYPE TYPE      FILENAME                                           BUFFER_SIZE BUFFER_COUNT OPEN_TIME           CLOSE_TIME--------- ----------- --------- -------------------------------------------------- ----------- ------------ ------------------- -------------------       83 DISK        AGGREGATE                                                              0            0 2019-05-10 17:16:28 2019-05-10 17:20:28       83 DISK        INPUT     /mnt/ramdisk/book/T01dbf                                524288            6 2019-05-10 17:16:28 2019-05-10 17:20:28       83 DISK        INPUT     /mnt/ramdisk/book/T02dbf                                524288            6 2019-05-10 17:16:28 2019-05-10 17:20:28       83 DISK        INPUT     /mnt/ramdisk/book/T03dbf                                524288            6 2019-05-10 17:16:32 2019-05-10 17:20:28       83 DISK        INPUT     /mnt/ramdisk/book/T04dbf                                524288            6 2019-05-10 17:16:36 2019-05-10 17:20:28       83 DISK        INPUT     /mnt/ramdisk/book/T05dbf                                524288            6 2019-05-10 17:16:40 2019-05-10 17:20:28       83 DISK        OUTPUT    /home/oracle/backup/t12345_1007918188_2ju1773c_1_1     1048576            4 2019-05-10 17:16:28 2019-05-10 17:20:287 rows selected.--//注意看OPEN_TIME的时间,间隔4秒.顺序启动读取T03,T04,T05.--//单个输入缓存512K ,512*6=3M.--//开始启动同时读取T01,T02--//也就是写出512K时,开始读取T03.再写出512K,读取T04.再再写出512K时,读取T05.--//而512K就是一个input buffer 的大小,也就是开始阶段写完1个input buffer到output buffer,读取新数据文件.4.如果我验证备份时3个文件,T03读取是8秒以后就可以验证我的判断.RMAN> backup  datafile 9,10,11 format '/home/oracle/backup/t1_%t_%U' ;Starting backup at 2019-05-10 17:28:09using channel ORA_DISK_1channel ORA_DISK_1: starting full datafile backup setchannel ORA_DISK_1: specifying datafile(s) in backup setinput datafile file number=00009 name=/mnt/ramdisk/book/T01dbfinput datafile file number=00010 name=/mnt/ramdisk/book/T02dbfinput datafile file number=00011 name=/mnt/ramdisk/book/T03dbfchannel ORA_DISK_1: starting piece 1 at 2019-05-10 17:28:09channel ORA_DISK_1: finished piece 1 at 2019-05-10 17:30:34piece handle=/home/oracle/backup/t1_1007918889_2mu177p9_1_1 tag=TAG20190510T172809 comment=NONEchannel ORA_DISK_1: backup set complete, elapsed time: 00:02:25channel ORA_DISK_1: throttle time: 0:02:24Finished backup at 2019-05-10 17:30:34SELECT set_count        ,device_type        ,TYPE        ,filename        ,buffer_size        ,buffer_count        ,open_time        ,close_time    FROM v$backup_async_io   where set_count=86ORDER BY set_count        ,TYPE        ,open_time        ,close_time;SET_COUNT DEVICE_TYPE TYPE      FILENAME                                       BUFFER_SIZE BUFFER_COUNT OPEN_TIME           CLOSE_TIME--------- ----------- --------- ---------------------------------------------- ----------- ------------ ------------------- -------------------       86 DISK        AGGREGATE                                                          0            0 2019-05-10 17:28:09 2019-05-10 17:30:33       86 DISK        INPUT     /mnt/ramdisk/book/T01dbf                           1048576            5 2019-05-10 17:28:09 2019-05-10 17:30:33       86 DISK        INPUT     /mnt/ramdisk/book/T02dbf                           1048576            5 2019-05-10 17:28:09 2019-05-10 17:30:33       86 DISK        INPUT     /mnt/ramdisk/book/T03dbf                           1048576            5 2019-05-10 17:28:17 2019-05-10 17:30:33       86 DISK        OUTPUT    /home/oracle/backup/t1_1007918889_2mu177p9_1_1     1048576            4 2019-05-10 17:28:09 2019-05-10 17:30:33--//注意看OPEN_TIME的时间,间隔8秒.启动读取T03.--//单个输入缓存1024K ,1024*5=3M.--//开始启动同时读取T01,T02--//也就是写出1M时,开始读取T03.--//而1024K就是一个input buffer 的大小,也就是开始阶段写完1个input buffer到output buffer,读取新数据文件.--//贴出4个文件的情况:RMAN> backup  datafile 9,10,11,12 format '/home/oracle/backup/t1_%t_%U' ;Starting backup at 2019-05-10 17:35:43using channel ORA_DISK_1channel ORA_DISK_1: starting full datafile backup setchannel ORA_DISK_1: specifying datafile(s) in backup setinput datafile file number=00009 name=/mnt/ramdisk/book/T01dbfinput datafile file number=00010 name=/mnt/ramdisk/book/T02dbfinput datafile file number=00011 name=/mnt/ramdisk/book/T03dbfinput datafile file number=00012 name=/mnt/ramdisk/book/T04dbfchannel ORA_DISK_1: starting piece 1 at 2019-05-10 17:35:43channel ORA_DISK_1: finished piece 1 at 2019-05-10 17:38:58piece handle=/home/oracle/backup/t1_1007919343_2nu1787f_1_1 tag=TAG20190510T173543 comment=NONEchannel ORA_DISK_1: backup set complete, elapsed time: 00:03:15channel ORA_DISK_1: throttle time: 0:03:12Finished backup at 2019-05-10 17:38:58SET_COUNT DEVICE_TYPE TYPE      FILENAME                                           BUFFER_SIZE BUFFER_COUNT OPEN_TIME           CLOSE_TIME--------- ----------- --------- -------------------------------------------------- ----------- ------------ ------------------- -------------------       87 DISK        AGGREGATE                                                              0            0 2019-05-10 17:35:43 2019-05-10 17:38:55       87 DISK        INPUT     /mnt/ramdisk/book/T01dbf                               1048576            4 2019-05-10 17:35:43 2019-05-10 17:38:55       87 DISK        INPUT     /mnt/ramdisk/book/T02dbf                               1048576            4 2019-05-10 17:35:43 2019-05-10 17:38:55       87 DISK        INPUT     /mnt/ramdisk/book/T03dbf                               1048576            4 2019-05-10 17:35:51 2019-05-10 17:38:55       87 DISK        INPUT     /mnt/ramdisk/book/T04dbf                               1048576            4 2019-05-10 17:35:59 2019-05-10 17:38:55       87 DISK        OUTPUT    /home/oracle/backup/t1_1007919343_2nu1787f_1_1         1048576            4 2019-05-10 17:35:43 2019-05-10 17:38:556 rows selected.--//自己看,不再解析了.