在Oracle数据库中出行的AMS|FS各代表什么存储方式?
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发布时间：2022-04-08 10:50
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时间：2022-04-08 15:12
五、 目录及目录文件管理
5.1 创建目录
SQL> alter diskgroup ASMGROUP1 add directory ‘+ASMGROUP1/WWL1‘;
Diskgroupaltered.
5.2 修改目录
SQL> alterdiskgroup ASMGROUP1 rename directory ‘+ASMGROUP1/WWL1‘ to ‘+ASMGROUP1/WWL2‘;
Diskgroupaltered.
5.3 删除目录
SQL> alter diskgroup ASMGROUP1 drop directory ‘+ASMGROUP1/WWL2‘;
Diskgroupaltered.
六、 手动平衡磁盘组
一般情况下ASM都会自动对其下的磁盘组进行平衡，不过ORACLE也提供了手动平衡磁盘组的方式，通过alter diskgroup ... power 语句。前面提到过磁盘组的平衡度有0到11多个级别，默认是按照ASM_POWER_LIMIT初始化参数中设置的值，手动平衡的话，设置的平衡度可以与初始化参数中并不相同，例如，设置磁盘组平衡度为5，语句如下：
SQL>alter diskgroup asmgroup1 rebalance power 5;
Diskgroup altered.
七、 通过ASMCMD工具管理ASM
[oracle@wwl ~]$ which asmcmd
/oracle/orahome/10.2.0/db_1/bin/asmcmd
[oracle@wwl ~]$ cd/oracle/orahome/10.2.0/db_1/bin/
ASMCMD> ls
ASMEXTERNAL/
ASMGROUP1/
ASMHIGH/
ASMNORMAL/
ASMCMD>
ASMCMD> help
asmcmd [-p] [command]
The environment variables ORACLE_HOME and ORACLE_SID determine the
instance to which the program connects, and ASMCMD establishes a
bequeath connection to it, in the same manner as a SQLPLUS / AS
SYSDBA. The user must be a memberof the SYSDBA group.
Specifying the -p option allows the current directory to be displayed
in the command prompt, like so:
ASMCMD [+DATAFILE/ORCL/CONTROLFILE] >
[command] specifies one of the following commands, along with its
parameters.
Type "help [command]" to get help on a specific ASMCMDcommand.
commands:
--------
cd：------------------------------------------进入下级目录或进入所需要的目录
du：------------------------------------------显示指定的ASM目录下ASM文件占用的所有磁盘空间
find：-----------------------------------------查找所需的文件
help：-----------------------------------------显示帮助信息
ls：---------------------------------------------列出ASM目录下的内容及其属性
lsct：-------------------------------------------列出当前ASM客户端的信息
lsdg：-------------------------------------------列出所有磁盘组及其属性
mkalias：--------------------------------------为系统生成的文件名创建别名
mkdir：----------------------------------------创建新目录
pwd：------------------------------------------显示当前目录路径
rm：--------------------------------------------删除ASM目录下的某个文件或文件夹
rmalias：--------------------------------------删除别名
ASMCMD>
要查看某个命令的相信通过在命令前添加help来查看，如下:
ASMCMD> help cd
cd <dir>
Change the current directory to <dir>.
ASMCMD> help du
du [-H] [dir]
Display total space used for files located recursively under [dir],
similar to "du -s" under UNIX; default is the currentdirectory. Two
values are returned, both in units of megabytes. The first value does
not take into account mirroring of the diskgroup while the second does.
For instance, if a file occupies 100 MB of space, then it actually
takes up 200 MB of space on a normal redundancy diskgroup and 300 MB
of space on a high redundancy diskgroup.
[dir] can also contain wildcards.
The -H flag suppresses the column headers from the output.
ASMCMD> help find
find [-t <type>] <dir> <pattern>
Find the absolute paths of all occurrences of <pattern> under<dir>.
<pattern> can be a directory and may include wildcards. <dir> may also
include wildcards. Note thatdirectory names in the results have the
"/" suffix to clarify their identity.
The -t option allows searching by file type. For instance, one can
search for all the control files at once. <type> must be one of the
valid values in V$ASM_FILE.TYPE.
ASMCMD>
八、 oracleasm工具的使用和语法介绍
[root@wwl ~]# oracleasm --help
Usage: oracleasm[--exec-path=<exec_path>] <command> [ <args> ]
oracleasm --exec-path
oracleasm -h
oracleasm -V
The basic oracleasm commands are:
configure Configure the OracleLinux ASMLib driver
init Load andinitialize the ASMLib driver
exit Stop the ASMLibdriver
scandisks Scan the systemfor Oracle ASMLib disks
status Display thestatus of the Oracle ASMLib driver
listdisks List known OracleASMLib disks
querydisk Determine if adisk belongs to Oracle ASMlib
createdisk Allocate a devicefor Oracle ASMLib use
deletedisk Return a deviceto the operating system
renamedisk Change the labelof an Oracle ASMlib disk
update-driver Download thelatest ASMLib driver
[root@wwl ~]#
九、 ASM相关视图（V$）和数据字典（X$）
ASM由于其高度的封装性，使得我们很难知道窥探其内部的原理。可以通过一下视图和数据字典来来查看ASM 的信息。
相关视图和数据字典
View Name
X$ Table name
Description
V$ASM_DISKGROUP
X$KFGRP
performs disk discovery and lists diskgroups
V$ASM_DISKGROUP_STAT
X$KFGRP_STAT
diskgroup stats without disk discovery
V$ASM_DISK
X$KFDSK, X$KFKID
performs disk discovery, lists disks and their usage metrics
V$ASM_DISK_STAT
X$KFDSK_STAT, X$KFKID
lists disks and their usage metrics
V$ASM_FILE
X$KFFIL
lists ASM files, including metadata/asmdisk files
V$ASM_ALIAS
X$KFALS
lists ASM aliases, files and directories
V$ASM_TEMPLATE
X$KFTMTA
lists the available templates and their properties
V$ASM_CLIENT
X$KFNCL
lists DB instances connected to ASM
V$ASM_OPERATION
X$KFGMG
lists rebalancing operations
N.A.
X$KFKLIB
available libraries, includes asmlib path
N.A.
X$KFDPARTNER
lists disk-to-partner relationships
N.A.
X$KFFXP
extent map table for all ASM files
N.A.
X$KFDAT
extent list for all ASM disks
N.A.
X$KFBH
describes the ASM cache (buffer cache of ASM in blocks of 4K (_asm_blksize)
N.A.
X$KFCCE
a linked list of ASM blocks. to be further investigated
This list isobtained querying v$fixed_view_definitionwhere view_name like ‘%ASM%‘ whichexposes all the v$ and gv$ views with theirdefinition. Fixed tables are exposedby querying v$fixed_table where name like‘x$kf%‘ (ASM fixed tables use the‘X$KF‘ prefix).
SQL>select* fromv$fixed_view_definition whereview_name like ‘%ASM%‘;
SQL>select* from sys.v$fixed_tablewhere name like ‘X$KF%‘ ;
十、 ASM常见的错误处理
错误一、
ORA-15097：cannotSHUTDOWN ASM instance with connected RDBMS instance
解决办法：
发生这个问题，唯一的一个原因就是Oracle实例没有关闭，或ORACLE实例正在关闭或处于挂起状态，导致ASM实例无法关闭，解决办法，关闭RDBMS实例后再关闭ASM实例。
错误二、
[root@wwl ~]# /etc/init.d/oracleasm createdisk VOL3 /dev/sdd
Marking disk "VOL3" as an ASM disk: [FAILED]
报这个错的原因在于磁盘为分区导致。在创建ASM的之前必须线将磁盘分区，但不能格式化，后执行创建就不会有问题了。
十一、 ASM 扩展性
最多支持63个磁盘组； 最多支持10000个磁盘； 最大支持4pb/磁盘； 最大支持40 exabyte/ASM存储； 最大支持1百W个文件/磁盘组； 外部冗余时单个文件最大35tb，标准冗余时单个文件最大5.8tb，高冗余度时单个文件最大3.9tb
十二、 ASM其它信息请参考如下连接：
http://docs.oracle.com/cd/E11882_01/server.112/e16102/asmfiles.htm
本文出自 “IT小矮人！” 博客，请务必保留此出处http://lqx049.blog.51cto.com/1919902/1703043
ORACLE之ASM概念
标签：oracle 数据库 asm 操作系统
热心网友
时间：2022-04-08 12:20
FS就是普通的文件类型了。就是依靠操作系统提供的文件系统作存储了。
