[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.