第二章 ASM INSTANCE ASM实例类型： 10g以后ORACLE instance 类型增加了一种ASM类型，参数INSTANCE_TYPE=ASM进行设置。
ASM实例启动命令： startup
nomount启动实例和后台进程，但没有挂载磁盘组
mount以后，实例会启动参数文件中ASM_DISKGROUPS指定的磁盘组，如果参数为空就会触发ORA-15110报错信息。 ASM 11G以后为mount命令引入了
restricted启动参数，以排他方式启动ASM_DISKGROUPS指定的磁盘组， 限制RDBMS访问磁盘组，restricted命令在维护磁盘组或rebalance时特别有用。 注意：resticted可以以磁盘组级别挂载磁盘组，而不是实例级别，好处是提供了细粒度的限制。 如：
| alter diskgroup data mount restricted; select name,state from v$asm_diskgroup; NAME STATE ---------------------- ------------------- DATA RESTRICTED |
后台进程： ASM后台进程都是以asm_开头的，就像rdbms是以ora_开头一样。 11g asm 后台进程介绍
ARBx These are the slave processes that do the rebalance activity (where x
is a number).
CKPTThe CKPTprocess manages cross-instance calls (in RAC).
DBWR This process manages the SGA buffer cache in the ASM instance.
DBW Rwrites out dirty buffers (changed metadata buffers) from the ASM
buffer cache to disk.
GMON This process is responsible for managing the disk-level activities
(drop/offline) and advancing diskgroup compatibility.
KATE The Konductor or ASM Temporary Errands (KATE) process is used
to process disks online. This process runs in the ASM instance and is started
only when an offlined disk is onlined.
LGWRThe LGWRprocess maintains the ASM Active Change Directory
(ACD) buffers from the ASM instance and flushes ACD change records to
disk.
MARK The Mark Allocation Unit (AU) for Resync Koordinator (MARK)
process coordinates the updates to the Staleness Registry when the disks go
offline. This process runs in the RDBMS instance and is started only when
disks go offline in ASM redundancy diskgroups.
PINGThe PINGprocess measures network latency and has the same
functionality in RDBMS instances.
PMON This manages processes and process death in the ASM instance.
PSP0 This process spawner process is responsible for creating and
managing other Oracle processes.
PZ9x These processes are parallel slave processes (where xis a number),
used in fetching data on behalf of GV$queries.
RBAL This opens all device files as part of discovery and coordinates the
rebalance activity.
SMON This process is the system monitor and also acts as a liaison to the
Cluster Synchronization Services (CSS) process (in Oracle Clusterware) for
node monitoring.
VKTM This process is used to maintain the fast timer and has the same
functionality in the RDBMS instances. |
ASM SGA和参数设置 ASM启动只需要很少的参数，参数文件可以是pfile也可以是spfile
*.instance_type=asm
*.asm_diskgroups=DATA,FLASH
*.processes=100
**** Note that asm_diskstring is site-specific and platform specific
*.asm_diskstring='/dev/rdsk/c3t19d*s4' --注意如果手动添加asm 磁盘组别忘记更新这个参数不然重启后缺少的盘组无法自动带起来
*.remote_login_passwordfile='SHARED'
******
**For 11g use only the diagnostics directory.
*.diagnostic_dest='/opt/app/admin/+ASM/diag' --11g的diagnostic_dest取代了10g的bdump，cdump，udump显然简介多了
*******
**For 10g use the standard dump locations
*.background_dump_dest='/opt/app/admin/+ASM/bdump'
*.core_dump_dest='/opt/app/admin/+ASM/cdump'
*.user_dump_dest='/opt/app/admin/+ASM/udump'
******* |
BACKGROUND_DUMP_DEST,CORE_DUMP_DEST, and USER_DUMP_DEST这三个参数在11g中已经弃用了，ASM实例中不要配置这三个参数了。如果diagnostic_dest没有配置，默认位置为$ORACLE_BASE/diag 例如下面的目录结构会被创建： $ORACLE_BASE/diag///
SQL> SELECT NAME, VALUE FROM V$DIAG_INFO
NAME VALUE
---------- ---------------
Diag Enabled TRUE
ADR Base /u01/app/oracle
ADR Home /u01/app/oracle /diag/asm/+asm/+ASM1
Diag Trace /u01/app/oracle |
|