[20190517]rman tape compressed.txt

[20190517]rman tape compressed.txt --//前一段测试rman选择压缩备份时,如果备份单个数据文件小于64M-3*8K时,先建立大小64M文件,最后会回收到自己的备份大小. --//链接：[20190509]rman备份的疑问5.txt --//测试也说明开始建立的文件时稀疏文件,自己有1个奇怪的想法,如果使用磁带方式，磁带是流式设备，oracle的rman会如何处理这 --//些细节呢？不管结果如何,还是通过测试说明问题。 1.环境： SCOTT@book> @ &r/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 CREATE TABLESPACE T01 DATAFILE '/mnt/ramdisk/book/t01.dbf' SIZE 40M AUTOEXTEND OFF LOGGING ONLINE EXTENT MANAGEMENT LOCAL AUTOALLOCATE BLOCKSIZE 8K SEGMENT SPACE MANAGEMENT MANUAL; ALTER DATABASE DATAFILE '/mnt/ramdisk/book/t01.dbf' RESIZE 65512K; create table t01 tablespace  t01 as select rownum id ,lpad('A',32,'A') name from dual connect by level<=7e5; 2.测试： --//说明我没有磁带,不过oracle提供模式磁带库的方式(实际上现在许多知名的备份软件实际上使用虚拟磁带库)。 CONFIGURE CHANNEL DEVICE TYPE SBT PARMS  'SBT_LIBRARY=oracle.disksbt,ENV=(BACKUP_DIR=/u01/backup)'; CONFIGURE DEFAULT DEVICE TYPE TO SBT_TAPE ; CONFIGURE CONTROLFILE AUTOBACKUP OFF; CONFIGURE CHANNEL 1 DEVICE TYPE DISK RATE 5M; --//执行如下: RMAN> CONFIGURE CHANNEL DEVICE TYPE SBT PARMS  'SBT_LIBRARY=oracle.disksbt,ENV=(BACKUP_DIR=/u01/backup)'; new RMAN configuration parameters: CONFIGURE CHANNEL DEVICE TYPE 'SBT_TAPE' PARMS  'SBT_LIBRARY=oracle.disksbt,ENV=(BACKUP_DIR=/u01/backup)'; new RMAN configuration parameters are successfully stored RMAN> CONFIGURE DEFAULT DEVICE TYPE TO SBT_TAPE ; old RMAN configuration parameters: CONFIGURE DEFAULT DEVICE TYPE TO DISK; new RMAN configuration parameters: CONFIGURE DEFAULT DEVICE TYPE TO 'SBT_TAPE'; new RMAN configuration parameters are successfully stored RMAN> CONFIGURE CONTROLFILE AUTOBACKUP OFF; old RMAN configuration parameters: CONFIGURE CONTROLFILE AUTOBACKUP OFF; new RMAN configuration parameters: CONFIGURE CONTROLFILE AUTOBACKUP OFF; new RMAN configuration parameters are successfully stored RMAN> CONFIGURE CHANNEL 1 DEVICE TYPE DISK RATE 1M; new RMAN configuration parameters: CONFIGURE CHANNEL 1 DEVICE TYPE DISK RATE 1 M; new RMAN configuration parameters are successfully stored --//还原脚本: --//CONFIGURE CHANNEL DEVICE TYPE SBT_TAPE clear; --//CONFIGURE DEFAULT DEVICE TYPE TO DISK; --//建立测试脚本: $ cat ts.sh #! /bin/bash file=$1 >| /tmp/xx_${file} >| /tmp/yy_${file} strace -ftt -x -o /tmp/tt_${file}.txt rman target / <<< "backup as compressed backupset datafile "$file" format \"/u01/backup/T_"${file}"_%U\" ;" & seq 30 | xargs -I{} echo "ls -l /u01/backup/T_${file}_*;sleep 0.5" | bash 2>/dev/null| ts.awk >> /tmp/xx_${file} 2>/dev/null & seq 30 | xargs -I{} echo "stat -c '%s %b %B' /u01/backup/T_${file}_*;sleep 0.5" | bash  2>/dev/null | ts.awk >> /tmp/yy_${file} 2>/dev/null & wait $ . ts.sh 9 Recovery Manager: Release 11.2.0.4.0 - Production on Wed May 22 08:46:31 2019 Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved. connected to target database: BOOK (DBID=1337401710) RMAN> Starting backup at 2019-05-22 08:46:34 using target database control file instead of recovery catalog allocated channel: ORA_SBT_TAPE_1 channel ORA_SBT_TAPE_1: SID=59 device type=SBT_TAPE channel ORA_SBT_TAPE_1: WARNING: Oracle Test Disk API channel ORA_SBT_TAPE_1: starting compressed full datafile backup set channel ORA_SBT_TAPE_1: specifying datafile(s) in backup set input datafile file number=00009 name=/mnt/ramdisk/book/t01.dbf channel ORA_SBT_TAPE_1: starting piece 1 at 2019-05-22 08:46:36 channel ORA_SBT_TAPE_1: finished piece 1 at 2019-05-22 08:46:37 piece handle=/u01/backup/T_9_2tu25tnc_1_1 tag=TAG20190522T084635 comment=API Version 2.0,MMS Version 8.1.3.0 channel ORA_SBT_TAPE_1: backup set complete, elapsed time: 00:00:01 Finished backup at 2019-05-22 08:46:37 RMAN> Recovery Manager complete. [1]   Done                    strace -ftt -x -o /tmp/tt_${file}.txt rman target / <<< "backup as compressed backupset datafile "$file" format \"/u01/backup/T_"${file}"_%U\" ;" [2]-  Done                    seq 30 | xargs -I{} echo "ls -l /u01/backup/T_${file}_*;sleep 0.5" | bash 2> /dev/null | ts.awk >> /tmp/xx_${file} 2> /dev/null [3]+  Done                    seq 30 | xargs -I{} echo "stat -c '%s %b %B' /u01/backup/T_${file}_*;sleep 0.5" | bash 2> /dev/null | ts.awk >> /tmp/yy_${file} 2> /dev/null $ ls -l  Oracle_Disk_SBT_Catalog T_9_2tu25tnc_1_1 -rw-r--r-- 1 oracle oinstall    3360 2019-05-22 08:46:36 Oracle_Disk_SBT_Catalog -rw-r--r-- 1 oracle oinstall 8388624 2019-05-22 08:46:36 T_9_2tu25tnc_1_1 $ cat /tmp/xx_9 [2019-05-22 08:46:36] -rw-r--r-- 1 oracle oinstall 4194320 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:37] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:37] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:38] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:38] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:39] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:39] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:40] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:40] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:41] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:41] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:42] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:42] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:43] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:43] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:44] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:44] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:45] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:45] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 [2019-05-22 08:46:46] -rw-r--r-- 1 oracle oinstall 8388624 May 22 08:46 /u01/backup/T_9_2tu25tnc_1_1 $ cat /tmp/yy_9 [2019-05-22 08:46:36] 4194320 8208 512 [2019-05-22 08:46:37] 8388624 16416 512 [2019-05-22 08:46:37] 8388624 16416 512 [2019-05-22 08:46:38] 8388624 16416 512 [2019-05-22 08:46:38] 8388624 16416 512 [2019-05-22 08:46:39] 8388624 16416 512 [2019-05-22 08:46:39] 8388624 16416 512 [2019-05-22 08:46:40] 8388624 16416 512 [2019-05-22 08:46:40] 8388624 16416 512 [2019-05-22 08:46:41] 8388624 16416 512 [2019-05-22 08:46:41] 8388624 16416 512 [2019-05-22 08:46:42] 8388624 16416 512 [2019-05-22 08:46:42] 8388624 16416 512 [2019-05-22 08:46:43] 8388624 16416 512 [2019-05-22 08:46:43] 8388624 16416 512 [2019-05-22 08:46:44] 8388624 16416 512 [2019-05-22 08:46:44] 8388624 16416 512 [2019-05-22 08:46:45] 8388624 16416 512 [2019-05-22 08:46:45] 8388624 16416 512 [2019-05-22 08:46:46] 8388624 16416 512 --//4194320/1024/1024 = 4.0000152587890625 0.0000152587890625*1024*1024  = 16 --//你可以发现备份文件集并没有建立稀疏文件.而且一开始就建立大小大于4M+16字节的文件. --//8388624/1024/1024 = 8.00001525878906250000,最后大小是压缩的. $ strings T_9_2tu25tnc_1_1 | grep AAAAAAAAAAAAAAAAAAAAAAAA|wc   64579  109753 2336114 --//有点奇怪的是仅仅看到AAAAAAAAAAAAAAAAAAAAAAAA是64579,应该至少7E5. --//700000-64579  = 635421有这么多AAAAA涉及压缩. SCOTT@book> select sum(bytes)/1024/1024 from dba_extents where file_id=9; SUM(BYTES)/1024/1024 --------------------                   33 --//33M.这么讲实际上还是存在可以实现压缩的. $ strings -t d T_9_2tu25tnc_1_1 | grep AAAAAAAAAAAAAAAAAAAAAAAA| tail 4193914  AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA, 4193955  AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA, 4193996  AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA, 4194037  AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA, 4194078  AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA, 4194119  AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA, 4194160  AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA, 4194201  AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA, 4194242  AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA, 4194283  AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA --//最后1个AAAAA出现的位置在4194283,4194283/1024/1024 = 3.99997997283935546875,前面4M之内. --//也就是可以大致推断前面4M是不压缩的,后面才压缩.不然建立的备份文件不会是8M. 3.重新测试: $ cat dx.sql drop tablespace t&1 including contents and datafiles; CREATE TABLESPACE T&1 DATAFILE '/mnt/ramdisk/book/T&1..dbf' SIZE 40M 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<=7e5; SCOTT@book> @ dx.sql 01 B old   1: drop tablespace t&1 including contents and datafiles new   1: drop tablespace t01 including contents and datafiles Tablespace dropped. old   1: CREATE TABLESPACE T&1 DATAFILE '/mnt/ramdisk/book/T&1..dbf' SIZE 40M AUTOEXTEND OFF LOGGING ONLINE EXTENT MANAGEMENT LOCAL AUTOALLOCATE BLOCKSIZE 8K SEGMENT SPACE MANAGEMENT AUTO FLASHBACK ON new   1: CREATE TABLESPACE T01 DATAFILE '/mnt/ramdisk/book/T01.dbf' SIZE 40M AUTOEXTEND OFF LOGGING ONLINE EXTENT MANAGEMENT LOCAL AUTOALLOCATE BLOCKSIZE 8K SEGMENT SPACE MANAGEMENT AUTO FLASHBACK ON Tablespace created. old   1: 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<=6e5 new   1: create table t01 tablespace t01 as select rownum id ,to_char(rownum,'FM000000')||lpad('B',26,'B') name from dual connect by level<=6e5 Table created. --//删除前面的备份重复测试. --//RMAN> delete backupset ; $ . ts.sh 9 Recovery Manager: Release 11.2.0.4.0 - Production on Wed May 22 09:07:27 2019 Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved. connected to target database: BOOK (DBID=1337401710) RMAN> Starting backup at 2019-05-22 09:07:30 using target database control file instead of recovery catalog allocated channel: ORA_SBT_TAPE_1 channel ORA_SBT_TAPE_1: SID=114 device type=SBT_TAPE channel ORA_SBT_TAPE_1: WARNING: Oracle Test Disk API channel ORA_SBT_TAPE_1: starting compressed full datafile backup set channel ORA_SBT_TAPE_1: specifying datafile(s) in backup set input datafile file number=00009 name=/mnt/ramdisk/book/T01.dbf channel ORA_SBT_TAPE_1: starting piece 1 at 2019-05-22 09:07:32 channel ORA_SBT_TAPE_1: finished piece 1 at 2019-05-22 09:07:33 piece handle=/u01/backup/T_9_2uu25uuk_1_1 tag=TAG20190522T090732 comment=API Version 2.0,MMS Version 8.1.3.0 channel ORA_SBT_TAPE_1: backup set complete, elapsed time: 00:00:01 Finished backup at 2019-05-22 09:07:33 RMAN> Recovery Manager complete. [1]   Done                    strace -ftt -x -o /tmp/tt_${file}.txt rman target / <<< "backup as compressed backupset datafile "$file" format \"/u01/backup/T_"${file}"_%U\" ;" [2]-  Done                    seq 30 | xargs -I{} echo "ls -l /u01/backup/T_${file}_*;sleep 0.5" | bash 2> /dev/null | ts.awk >> /tmp/xx_${file} 2> /dev/null [3]+  Done                    seq 30 | xargs -I{} echo "stat -c '%s %b %B' /u01/backup/T_${file}_*;sleep 0.5" | bash 2> /dev/null | ts.awk >> /tmp/yy_${file} 2> /dev/null SELECT set_count         ,device_type         ,TYPE         ,filename         ,buffer_size         ,buffer_count         ,open_time         ,close_time     FROM v$backup_async_io    where set_count=94 ORDER BY set_count         ,TYPE         ,open_time         ,close_time;  SET_COUNT DEVICE_TYPE       TYPE      FILENAME                       BUFFER_SIZE BUFFER_COUNT OPEN_TIME           CLOSE_TIME ---------- ----------------- --------- ------------------------------ ----------- ------------ ------------------- -------------------         94 DISK              AGGREGATE                                          0            0 2019-05-22 09:07:32 2019-05-22 09:07:32         94 DISK              INPUT     /mnt/ramdisk/book/T01.dbf          1048576           16 2019-05-22 09:07:32 2019-05-22 09:07:32 $ head -2 /tmp/xx_9  /tmp/yy_9 ==> /tmp/xx_9 <== [2019-05-22 09:07:32] -rw-r--r-- 1 oracle oinstall 4194320 May 22 09:07 /u01/backup/T_9_2uu25uuk_1_1 [2019-05-22 09:07:32] -rw-r--r-- 1 oracle oinstall 8388624 May 22 09:07 /u01/backup/T_9_2uu25uuk_1_1 --//(8388624-4194320)/1024/1024 = 4 ==> /tmp/yy_9 <== [2019-05-22 09:07:32] 4194320 8208 512 [2019-05-22 09:07:32] 8388624 16416 512 $ strings -t d T_9_2uu25uuk_1_1 | grep BBBBBBBBBBBBB| tail 4193913 % 062236BBBBBBBBBBBBBBBBBBBBBBBBBB, 4193954 $ 062235BBBBBBBBBBBBBBBBBBBBBBBBBB, 4193995 # 062234BBBBBBBBBBBBBBBBBBBBBBBBBB, 4194036 o 062233BBBBBBBBBBBBBBBBBBBBBBBBBB, 4194077 ! 062232BBBBBBBBBBBBBBBBBBBBBBBBBB, 4194118   062231BBBBBBBBBBBBBBBBBBBBBBBBBB, 4194160  062230BBBBBBBBBBBBBBBBBBBBBBBBBB, 4194201  062229BBBBBBBBBBBBBBBBBBBBBBBBBB, 4194242  062228BBBBBBBBBBBBBBBBBBBBBBBBBB, 4194283  062227BBBBBBBBBBBBBBBBBBBBBBBBBB SCOTT@book> select rowid,t01.* from t01 where id=062227; ROWID                      ID NAME ------------------ ---------- ---------------------------------------- ACgY2MAAJAAAAH/AAA      62227 062227BBBBBBBBBBBBBBBBBBBBBBBBBB SCOTT@book> @ rowid ACgY2MAAJAAAAH/AAA     OBJECT       FILE      BLOCK        ROW ROWID_DBA            DBA                  TEXT ---------- ---------- ---------- ---------- -------------------- -------------------- ----------------------------------------   42044812          9        511          0  0x24001FF           9,511                alter system dump datafile 9 block 511 ; --//在dba=9,511位置.511*8192 = 4186112 ,行号=0,数据从块底部开始插入.所以tail看到的最后1行是行号0. $ ls -l T_9_2uu25uuk_1_1 -rw-r--r-- 1 oracle oinstall 8388624 2019-05-22 09:07:32 T_9_2uu25uuk_1_1 --//可以看出使用磁盘模拟还是可以压缩的,仅仅前面4M不压缩(注我仅仅测试备份集包含单个文件的情况)为什么一些虚拟带库不支持压缩呢? --//另外视乎虚拟带库的文件建立按照4M大小建立的. --//看来应该建议他们测试看看,是否支持压缩方式.