标签:异步 app dbf oradata IO Oracle ASYNC u01
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
disk_asynch_io boolean TRUE
SQL> COL NAME FORMAT A50
SQL> SELECT NAME,ASYNCH_IO FROM V$DATAFILE F,V$IOSTAT_FILE I
WHERE F.FILE#=I.FILE_NO
AND FILETYPE_NAME='Data File'; 2 3
NAME ASYNCH_IO
-------------------------------------------------- ---------
/u01/app/oracle/oradata/yaoy11G/system01.dbf ASYNC_OFF
/u01/app/oracle/oradata/yaoy11G/sysaux01.dbf ASYNC_OFF
/u01/app/oracle/oradata/yaoy11G/undotbs01.dbf ASYNC_OFF
/u01/app/oracle/oradata/yaoy11G/users01.dbf ASYNC_OFF
/u01/app/oracle/oradata/yaoy11G/example01.dbf ASYNC_OFF
SQL> show parameter systemio
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
filesystemio_options string none
SQL> alter system set filesystemio_options=asynch;
alter system set filesystemio_options=asynch
*
ERROR at line 1:
ORA-02095: specified initialization parameter cannot be modified
SQL> alter system set filesystemio_options=setall scope=spfile;
System altered.OPTIONS:
"asynch" - This allows asynchronous IO to be used where supported by the OS.
"directIO" - This allows directIO to be used where supported by the OS. Direct IO bypasses any Unix buffer cache. As of 10.2 most platforms will try to use "directio" option for NFS mounted disks (and will also check NFS attributes are sensible).
"setall" - Enables both ASYNC and DIRECT IO.
"none" - This disables ASYNC IO and DIRECT IO so that Oracle uses normal synchronous writes, without any direct io options.
SQL> startup force;
ORACLE instance started.
Total System Global Area 835104768 bytes
Fixed Size 2217952 bytes
Variable Size 511707168 bytes
Database Buffers 318767104 bytes
Redo Buffers 2412544 bytes
Database mounted.
Database opened.
SQL> COL NAME FORMAT A50
SQL> SELECT NAME,ASYNCH_IO FROM V$DATAFILE F,V$IOSTAT_FILE I
WHERE F.FILE#=I.FILE_NO
AND FILETYPE_NAME='Data File'; 2 3
NAME ASYNCH_IO
-------------------------------------------------- ---------
/u01/app/oracle/oradata/yaoy11G/system01.dbf ASYNC_ON
/u01/app/oracle/oradata/yaoy11G/sysaux01.dbf ASYNC_ON
/u01/app/oracle/oradata/yaoy11G/undotbs01.dbf ASYNC_ON
/u01/app/oracle/oradata/yaoy11G/users01.dbf ASYNC_ON
/u01/app/oracle/oradata/yaoy11G/example01.dbf ASYNC_ON
As for ASM, ASM Inherently Performs Asynchronous I/O Regardless of filesystemio_options Parameter (Doc ID 751463.1)
FILESYSTEMIO_OPTIONS enables asynchronous I/O (AIO) when the value is set to SETALL/ASYNC. However, ASM bypasses the filesystem layer in this case because ASM I/O is entirely controlled by DISK_ASYNCH_IO parameter. AIO needs to be enabled/disabled by setting disk_asynch_io to parameter values TRUE/FALSE.
标签:异步,app,dbf,oradata,IO,Oracle,ASYNC,u01 来源: https://blog.csdn.net/weixin_43424368/article/details/101112281
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