ASM
ASM是 Oracle数据库 10g中一个非常出色的新特性,它以平台无关的方式提供了文件系统、逻辑卷管理器以及软件 RAID等服务。ASM可以条带化和镜像磁盘,从而实现了在数据库被加载的情况下添加或移除磁盘以及自动平衡 I/O以删除“热点”。它还支持直接和异步的 I/O并使用 Oracle9i中引入的 Oracle数据管理器 API(简化的 I/O系统调用接口)。
 
,ASM不是一个通用的文件系统
ASM不是一个通用的文件系统,并只能用于 Oracle数据文件、重做日志以及控制文件。ASM中的文件既可以由数据库自动创建和命名(通过使用 Oracle管理文件特性),也可以由 DBA手动创建和命名。由于操作系统无法访问 ASM中存储的文件,因此对使用 ASM文件的数据库执行备份和恢复操作的唯一途径就是通过恢复管理器 (RMAN)。
 
,ASM作为单独的Oracle实例实施
ASM作为单独的 Oracle实例实施,只有它在运行时其他数据库才能访问它。在 Linux上,只有运行 OCSSD服务(由 Oracle通用安装程序默认安装)才能使用 ASM。ASM需要的内存不多:对大多数系统,只需 64 MB。
 
,ASM提供了3种冗余方法。
external redundancy    表示Oracle不帮你管理镜像,功能由外部存储系统实现,比如通过RAID技术。
normal redundancy      (默认方式)表示Oracle提供2路镜像来保护数据。
high redundancy          表示Oracle提供3路镜像来保护数据。
 
,oracle通过failure group来提供高可用性。
ASM的镜像算法是extent级别,而不是整个磁盘级别。这里面有个primary copy和second copy的概念;写入的时候依据primary copy,最终实现写入随机有序读取,来完成平衡数据读取的目的。
 
,ASM实例只需要初始参数文件,不需要其它物理文件.
[oracle@kk dbs]$ cat  /opt/oracle/product/10.2.0/db_1/dbs/spfile+ASM.ora  <==初始化参数文件的位置
1O7*+ASM.asm_diskgroups='ASMGRP1'#Manual Mount
*.asm_diskgroups='ASMGRP1'
*.background_dump_dest='/opt/oracle//admin/+ASM/bdump'
*.core_dump_dest='/opt/oracle//admin/+ASM/cdump'
*.instance_type='asm'
*.large_pool_size=12M
*.remote_login_passwordfile='SHARED'
*.user_dump_dest='/opt/oracle//admin/+ASM/udump'
 
,ASM的实例的名称是+ASM。INSTANCE_TYPE=ASM
SQL> select instance_name from v$instance;
INSTANCE_NAME
--------------------------------
+ASM
 
8,ASM实例的控制文件
SQL> SHOW parameter control
 
NAME                          TYPE             VALUE
------------------------------           -------------         --------------------------------------------------
control_file_record_keep_time        integer            7
control_files                       string            /opt/oracle/product/10.2.0/db_1/dbs/cntrl+ASM.dbf

,确认自己系统版本
[root@kk 32bit]# uname –rm   <==查看系统信息,下载合适的软件
2.6.18-92.el5 i686
 
 
,下载对应的软件
软件下载地址:http://www.oracle.com/technology/tech/linux/asmlib/index.html
 
,安装,注意安装顺序
[root@kk 32bit]# rpm -ivh oracleasm-support-2.1.3-1.el5.i386.rpm
warning: oracleasm-support-2.1.3-1.el5.i386.rpm: Header V3 DSA signature: NOKEY, key ID 1e5e0159
Preparing...               ########################################### [100%]
  1:oracleasm-support     ########################################### [100%]
 
[root@kk 32bit]# rpm -ivh oracleasm-2.6.18-92.el5-2.0.5-1.el5.i686.rpm
warning: oracleasm-2.6.18-92.el5-2.0.5-1.el5.i686.rpm: Header V3 DSA signature: NOKEY, key ID 1e5e0159
Preparing...               ########################################### [100%]
  1:oracleasm-2.6.18-92.el5########################################### [100%]
 
[root@kk 32bit]# rpm -ivh oracleasmlib-2.0.4-1.el5.i386.rpm
warning: oracleasmlib-2.0.4-1.el5.i386.rpm: Header V3 DSA signature: NOKEY, key ID 1e5e0159
Preparing...               ########################################### [100%]
  1:oracleasmlib          ########################################### [100%]
 
 

,使用ASM前线关闭selinux
 [root@kk 32bit]# vi /etc/selinux/config  <==关闭selinux,否则会报错
SELINUX=enforcing
改为
SELINUX=disabled
 
[root@kk Server]# setenforce 0
 
,运行配置脚本,准备ASMLib驱动程序
[root@kk 32bit]# /etc/init.d/oracleasm configure   <==使用 ASMLib之前,必须运行配置脚本以准备驱动程序
Configuring the Oracle ASM library driver.
 
This will configure the on-boot properties of the Oracle ASM library
driver. The following questions will determine whether the driver is
loaded on boot and what permissions it will have. The current values
will be shown in brackets ('[]'). Hitting without typing an
answer will keep that current value. Ctrl-C will abort.
 
Default user to own the driver interface []: oracle
Default group to own the driver interface []: dba
Start Oracle ASM library driver on boot (y/n) [n]: y
Scan for Oracle ASM disks on boot (y/n) [y]:y
Writing Oracle ASM library driver configuration: done
Initializing the Oracle ASMLib driver:                    [ OK ]
Scanning the system for Oracle ASMLib disks:             [ OK ]
 
,启用ASMLib驱动程序
[root@kk 32bit]# /etc/init.d/oracleasm enable <==启用 ASMLib 驱动程序
Writing Oracle ASM library driver configuration: done
Initializing the Oracle ASMLib driver:                    [ OK ]
Scanning the system for Oracle ASMLib disks:              [ OK ]
 
[root@kk 32bit]# fdisk –l  <==查看系统都挂载了那些磁盘
Disk /dev/sdb: 4294 MB, 4294967296 bytes 
255 heads, 63 sectors/track, 522 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
 
  Device Boot     Start        End     Blocks  Id System
/dev/sdb1              1        130    1044193+ 83 Linux
/dev/sdb2            131        250     963900  83 Linux
/dev/sdb3            251        522    2184840  83 Linux
,ASM的运行需要CSS服务,下面来安装它
首先安装CSS(Oracle Cluster Synchronization Service)
[root@kk 32bit]# cd /opt/oracle/product/10.2.0/db_1/bin/
[root@kk bin]# ./localconfig add                  <==执行这个命令来完成安装
/etc/oracle does not exist. Creating it now.
Successfully accumulated necessary OCR keys.
Creating OCR keys for user 'root', privgrp 'root'..
Operation successful.
Configuration for local CSS has been initialized
 
Adding to inittab
Startup will be queued to init within 90 seconds.
Checking the status of new Oracle init process...
Expecting the CRS daemons to be up within 600 seconds.
CSS is active on these nodes.
  kk
CSS is active on all nodes.
Oracle CSS service is installed and running under init(1M)
 
 
,创建ASM磁盘
注意:VOL* :这里必须要大写,否则会出错
 /dev/sdb*:这里可以是整块未分区的硬盘也可以是硬盘的分区。
[root@kk 32bit]# /etc/init.d/oracleasm createdisk VOL1 /dev/sdb1
Marking disk "VOL1" as an ASM disk:                       [ OK ]
[root@kk 32bit]# /etc/init.d/oracleasm createdisk VOL2/dev/sdb2
Marking disk "VOL2" as an ASM disk:                       [ OK ]
[root@kk 32bit]# /etc/init.d/oracleasm createdisk VOL3/dev/sdb3
Marking disk "VOL3" as an ASM disk:                       [ OK ]
 
,查看已标记为ASMLib的硬盘
[root@kk 32bit]# /etc/init.d/oracleasm listdisks  <==查看已标记为ASMLib的硬盘
VOL1
VOL2
VOL3
 
 
,创建diskgroup
冗余
- High镜像数据两次。
- Normal镜像数据一次。
- External不镜像 ASM中的数据。如果外部 RAID阵列提供冗余,则通常使用此选项。 
 
SQL> select name,path,group_number from v$asm_disk;  <==查询asm_disk的名称和路径,一会创建时要用
 
NAME                         PATH                              GROUP_NUMBER
---------------------------------- ----------------------------------------------         -------------------------
                               ORCL:VOL4                             0  <==0说明该磁盘不属于任何组
VOL1                          ORCL:VOL1                             1
VOL2                          ORCL:VOL2                             1
VOL3                          ORCL:VOL3                             1
 
SQL> create diskgroup DISKGRP2 external redundancy disk  'ORCL:VOL4';
Diskgroup created.
 
,启动/关闭ASM实例
【原则】先关闭其它例程,最后关闭ASM例程
否则会报下面的错误
SQL> shutdown immediate;
ORA-15097: cannot SHUTDOWN ASM instance with connected RDBMS instance
 
启动顺序
案例:这里强调ASM实例启动只需要spfile.ora不需要其它任何物理数据文件!
SQL> startup
ORA-01078: failure in processing system parameters
LRM-00109: could not open parameter file '/opt/oracle/product/10.2.0/db_1/dbs/init+ASM.ora'
 
[oracle@kk ~]$ export ORACLE_SID=+ASM
[oracle@kk ~]$ sqlplus "/ as sysdba"
 
SQL*Plus: Release 10.2.0.1.0 - Production on Sat Mar 13 07:54:58 2010
 
Copyright (c) 1982, 2005, Oracle. All rights reserved.
 
Connected to an idle instance.
 
SQL> startup
ASM instance started
 
Total System Global Area  83886080 bytes
Fixed Size                 1217836 bytes
Variable Size             57502420 bytes
ASM Cache                 25165824 bytes
ASM diskgroups mounted
 
SQL> exit
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, Oracle Label Security, OLAP and Data Mining Scoring Engine options
[oracle@kk ~]$ exit
logout
[root@kk ~]# su - oracle
[oracle@kk ~]$ sqlplus "/ as sysdba"
 
SQL*Plus: Release 10.2.0.1.0 - Production on Sat Mar 13 07:55:36 2010
 
Copyright (c) 1982, 2005, Oracle. All rights reserved.
 
Connected to an idle instance.
 
SQL> startup
ORACLE instance started.
 
Total System Global Area 608174080 bytes
Fixed Size                 1220844 bytes
Variable Size            176164628 bytes
Database Buffers         427819008 bytes
Redo Buffers               2969600 bytes
Database mounted.
Database opened.
SQL>
目录
一,认识ASM 2
1,ASM   2
2,ASM不是一个通用的文件系统   2
3,ASM作为单独的 Oracle实例实施      2
4,ASM提供了3种冗余方法。        2
5,oracle通过failure group来提供高可用性。  2
6,ASM实例只需要初始参数文件,不需要其它物理文件. 2
7,ASM的实例的名称是+ASM。INSTANCE_TYPE=ASM         2
 
二,安装ASM 2
1,确认自己系统版本        2
2,下载对应的软件  3
3,安装,注意安装顺序    3
 
三,使用3
1,使用ASM前线关闭selinux  3
2,运行配置脚本,准备ASMLib驱动程序         3
3,启用ASMLib驱动程序         3
4,ASM的运行需要CSS服务,下面来安装它  4
5,创建ASM磁盘   4
6,查看已标记为ASMLib的硬盘      4
7,创建diskgroup     4
8,启动/关闭ASM实例    4
 
四,ASM相关视图及内部命令     5
1,查看asm diskgroup的名字、状态、复制类型、总大小、空闲空间      5
2,查看ASM磁盘的名字、路径、挂载状态、磁盘号   5
3,数据文件命名含义 dba_data_files     6
4,在ASM实例中查询文件编号和大小6
查询文件号及其大小     7
5,查询相关的物理文件的大小 7
6,ASM的内部命令 asmcmd    7
 
五,高级操作  8
1,创建或更改表空间   8
a,查询asm_diskgroup信息   8
b.创建表空间erp   8
c,观察磁盘组空间变化  8
d,dba_data_files中关于文件名称和大小的信息8
e,resize文件大小 8
2,删除disk     8
3,添加新硬盘并重新负载均衡 8
 
六,FAQ:  9
1,diskgroup的管理     9
2,条带化原理和rebalance  9
3,文件名和Template    9
4,ASMCMD命令行    9
5,ASM文件转化  9
6,Failure Groups in ASM     9
7,Oracle10g新增DBMS_FILE_TRANSFER包 9
 
正文:
相关视图及内部命令
,查看asm diskgroup的名字、状态、复制类型、总大小、空闲空间
SQL> select name, state, type, total_mb, free_mb from v$asm_diskgroup;
 
NAME                STATE           TYPE          TOTAL_MB   FREE_MB
--------------------   -----------------------      -----------------     -------------------  ----------
ASMGRP1         MOUNTED           NORMAL          6273        3616
DISKGRP2         MOUNTED           EXTERN          1913        1863
 
 
,查看ASM磁盘的名字、路径、挂载状态、磁盘号
SQL> select name, path, mode_status, state, disk_number from v$asm_disk;
 
NAME    PATH          MODE_STATUS    STATE              DISK_NUMBER
---------------------------------------------------------------------------------------------------------------------------------
VOL1    ORCL:VOL1      ONLINE         NORMAL                    0
VOL2    ORCL:VOL2      ONLINE         NORMAL                    1
VOL3    ORCL:VOL3      ONLINE         NORMAL                    2
VOL4    ORCL:VOL4      ONLINE         NORMAL                    0
 
,数据文件命名含义dba_data_files
SQL> select file_name from dba_data_files;
 
FILE_NAME
--------------------------------------------------------------------------------
+ASMGRP1/boy/datafile/users.259.713439439
+ASMGRP1/boy/datafile/sysaux.257.713439427
+ASMGRP1/boy/datafile/undotbs1.258.713439433
+ASMGRP1/boy/datafile/system.256.713439419
+ASMGRP1/boy/datafile/example.269.713440119
+DISKGRP2/boy/datafile/erp.256.713522125
 
格式说明:
+ASMGRP1/boy /datafile/tbs_name.asm_filenumber.incarnation_number
 
   + ASMGRP1: diskgroup名
            boy:  该数据库名
  datafile: 文件类型,表示是数据文件
 tbs_name:  表空间名
 asm file#: 表示ASM file编号,v$asm_file.file_number
incarnation number: 从时间戳提取,唯一值 。
 
,在ASM实例中查询文件编号和大小
[oracle@kk ~]$ export ORACLE_SID=+ASM
[oracle@kk ~]$ sqlplus '/as sysdba'
SQL> select file_number,bytes/1024/1024 from v$asm_file;
 
FILE_NUMBER BYTES/1024/1024
----------- ---------------
       256     480.007813
       257     250.007813
       258     25.0078125
       259     70.0078125
       260       6.734375
       261       6.734375
       262     50.0004883
       263     50.0004883
       264     50.0004883
       265     50.0004883
       266     50.0004883
       267     50.0004883
       268     20.0078125
       269     100.007813
       270     .002441406
       256     800.007813
 
SQL> select member from v$logfile;
 
MEMBER
--------------------------------------------------------------------------------
+ASMGRP1/boy/onlinelog/group_3.266.713439655
+ASMGRP1/boy/onlinelog/group_3.267.713439663
+ASMGRP1/boy/onlinelog/group_2.264.713439635
+ASMGRP1/boy/onlinelog/group_2.265.713439643
+ASMGRP1/boy/onlinelog/group_1.262.713439615
+ASMGRP1/boy/onlinelog/group_1.263.713439627
 
16 rows selected.
 
所查询到的值,与dba_data_files相匹配。
 

+ASM (ASM instance)
SQL> select file_number , sum(bytes)/(1024*1024)  MB from v$asm_file group by file_number;
 
FILE_NUMBER SUM(BYTES)/(1024*1024)
----------- ----------------------
       256            360.007813
       257            35.0078125
 
BOY (database instance)
SQL> select name from v$datafile
 
NAME
----------------------------------------
+DATA/orcl/datafile/sysaux.256.3
+DATA/orcl/datafile/system.258.3
+DATA/orcl/datafile/undotbs1.257.3
+DATA/orcl/datafile/users.265.3
+DATA/orcl/datafile/nitin.263.3
 
,查询相关的物理文件的大小
select sum(bytes)/(1024*1024*1024) from v$datafile;
 
select sum(bytes)/(1024*1024*1024) from v$logfile a, v$log b where a.group#=b.group#; 
 
select sum(bytes)/(1024*1024*1024) from v$tempfile where status='ONLINE';
 
,ASM的内部命令asmcmd
[oracle@kk ~]$ export ORACLE_SID=+ASM
[oracle@kk ~]$ asmcmd
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
       LANGUAGE = (unset),
       LC_ALL = (unset),
       LANG = "AMRICAN"
   are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
       LANGUAGE = (unset),
       LC_ALL = (unset),
       LANG = "AMRICAN"
   are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
ASMCMD> ls -l
State   Type   Rebal Unbal Name
MOUNTED NORMAL N     N     ASMGRP1/
MOUNTED EXTERN N     N     DISKGRP2/
ASMCMD [+ASMGRP1] > help
       commands:
       --------
       cd
       du
       find
       help
       ls
       lsct
       lsdg
       mkalias
       mkdir
       pwd
       rm
       rmalias
 
 

,创建或更改表空间
查询asm_diskgroup信息
SQL> select group_number,name, total_mb,free_mb from v$asm_diskgroup
 
GROUP_NUMBER     NAME                                TOTAL_MB   FREE_MB
------------ ------------------------------------------------------------       ----------       ----------
          1        ASMGRP1                                  6273        3616
          2        DISKGRP2                                 1913         1863
 
创建表空间erp
SQL> create tablespace erp datafile '+DISKGRP2' size 800m;
 
Tablespace created.
 
观察磁盘组空间变化
SQL> select group_number,name, total_mb,free_mb from v$asm_diskgroup;
 
GROUP_NUMBER   NAME                        TOTAL_MB FREE_MB
------------ ------------------------------------------------------------  ----------     ----------
          1      ASMGRP1                        6273      3616
          2     DISKGRP2                        1913      1060
,dba_data_files中关于文件名称和大小的信息
SQL>  select file_name,tablespace_name,bytes/1024/1024 MB,autoextensible from dba_data_files
FILE_NAME                              TABLESPACE_NAME        MB  AUTOEX
------------------------------------------------------------- ------------------------------------------------------------ ---------- ------
+ASMGRP1/boy/datafile/users.259.713439439    USERS                     5    YES
+ASMGRP1/boy/datafile/sysaux.257.713439427   SYSAUX                   240        YES
+ASMGRP1/boy/datafile/undotbs1.258.713439433 UNDOTBS1                25   YES
+ASMGRP1/boy/datafile/system.256.713439419   SYSTEM                   480 YES
+ASMGRP1/boy/datafile/example.269.713440119  EXAMPLE                 100  YES
+DISKGRP2/boy/datafile/erp.256.713522125      ERP                       800  NO
 
,resize文件大小
SQL> alter database datafile '+ASMGRP1/boy/datafile/users.259.713439439' resize 70M;
 
Database altered.
 
SQL> select file_name,tablespace_name,bytes/1024/1024 MB,autoextensible from dba_data_files;
 
FILE_NAME                                 TABLESPACE_NAME      MB                 AUTOEX
----------------------------------------------------------------- ------------------------------------------------------------ ---------- ------
+ASMGRP1/boy/datafile/users.259.713439439       USERS                  70        YES
 
,删除disk
SQL> select group_number, name from v$asm_diskgroup;
SQL> select path, name from v$asm_disk where group_number=1;
SQL> alter diskgroup DISKGRP2 drop disk VOL4;
 
Diskgroup altered.
 
,添加新硬盘并重新负载均衡
SQL> alter diskgroup DATA add disk '/dev/rdsk/c3t19d39s4' rebalance power 11 <==power:允许使用系统资源的一个参数
 
SQL> select * from v$asm_operation
 
 

,diskgroup的管理
http://space.itpub.net/?uid-354732-action-viewspace-itemid-627665
,条带化原理和rebalance
http://space.itpub.net/?uid-354732-action-viewspace-itemid-628992
,文件名和Template
http://space.itpub.net/?uid-354732-action-viewspace-itemid-629497
,ASMCMD命令行
http://space.itpub.net/?uid-354732-action-viewspace-itemid-629586
,ASM文件转化
http://space.itpub.net/?uid-354732-action-viewspace-itemid-629618
,Failure Groups in ASM
http://blog.chinaunix.net/u/19769/showart_244125.html
,Oracle10g新增DBMS_FILE_TRANSFER包
http://yangtingkun.itpub.net/post/468/484002
8, oracle wiki
http://www.orafaq.com/wiki/ASM_FAQ