[20190517]rman tape compressed.txt

--//前一段測試rman選擇壓縮備份時,如果備份單個資料檔案小於64M-3*8K時,先建立大小64M檔案,最後會回收到自己的備份大小.

--//連結：[20190509]rman備份的疑問5.txt

--//測試也說明開始建立的檔案時稀疏檔案,自己有1個奇怪的想法,如果使用磁帶方式，磁帶是流式裝置，oracle的rman會如何處理這

--//些細節呢？不管結果如何,還是透過測試說明問題。

1.環境：

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.測試：

--//說明我沒有磁帶,不過oracle提供模式磁帶庫的方式(實際上現在許多知名的備份軟體實際上使用虛擬磁帶庫)。

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;

--//執行如下:

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

--//還原指令碼:

--//CONFIGURE CHANNEL DEVICE TYPE SBT_TAPE clear;

--//CONFIGURE DEFAULT DEVICE TYPE TO DISK;

--//建立測試指令碼:

$ 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

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 08:46:38] -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 08:46:40] -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 08:46:42] -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 08:46:44] -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 08:46:46] -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 08:46:38] 8388624 16416 512

[2019-05-22 08:46:39] 8388624 16416 512

[2019-05-22 08:46:40] 8388624 16416 512

[2019-05-22 08:46:41] 8388624 16416 512

[2019-05-22 08:46:42] 8388624 16416 512

[2019-05-22 08:46:43] 8388624 16416 512

[2019-05-22 08:46:44] 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

--//你可以發現備份檔案集並沒有建立稀疏檔案.而且一開始就建立大小大於4M+16位元組的檔案.

--//8388624/1024/1024 = 8.00001525878906250000,最後大小是壓縮的.

$ strings T_9_2tu25tnc_1_1 | grep AAAAAAAAAAAAAAAAAAAAAAAA|wc

64579 109753 2336114

--//有點奇怪的是僅僅看到AAAAAAAAAAAAAAAAAAAAAAAA是64579,應該至少7E5.

--//700000-64579 = 635421有這麼多AAAAA涉及壓縮.

SCOTT@book> select sum(bytes)/1024/1024 from dba_extents where file_id=9;

SUM(BYTES)/1024/1024

--------------------

33

--//33M.這麼講實際上還是存在可以實現壓縮的.

$ 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

--//最後1個AAAAA出現的位置在4194283,4194283/1024/1024 = 3.99997997283935546875,前面4M之內.

--//也就是可以大致推斷前面4M是不壓縮的,後面才壓縮.不然建立的備份檔案不會是8M.

3.重新測試:

$ 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.

--//刪除前面的備份重複測試.

--//RMAN> delete backupset ;

$ . ts.sh 9

Recovery Manager: Release 11.2.0.4.0 - Production on Wed May 22 09:07:27 2019

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 ,行號=0,資料從塊底部開始插入.所以tail看到的最後1行是行號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

--//可以看出使用磁碟模擬還是可以壓縮的,僅僅前面4M不壓縮(注我僅僅測試備份集包含單個檔案的情況)為什麼一些虛擬帶庫不支援壓縮呢?

--//另外視乎虛擬帶庫的檔案建立按照4M大小建立的.

--//看來應該建議他們測試看看,是否支援壓縮方式.

[20190517]rman tape compressed.txt

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