After applying to the Exadata the January 2014 quarterly full stack patch and 11.2.0.4.3 RDBMS we run the IO Calibration dbms_resource_manger.calibrate_io(). It generated the messages in alert log trace files:
calibrate_io (kcfcagmdf): WARNING: ASync I/O not possible for datafile with file number (fno) [1]
calibrate_io (kcfcagmdf): WARNING: ASync I/O not possible for datafile with file number (fno) [2]
calibrate_io (kcfcagmdf): WARNING: ASync I/O not possible for datafile with file number (fno) [3]
calibrate_io (kcfcagmdf): WARNING: ASync I/O not possible for datafile with file number (fno) [4]
We checked the DB parameters:
SQL> show parameter filesystemio
NAME TYPE VALUE
-------------------- ------ ------
filesystemio_options string setall
SQL> show parameter disk_asynch_io
NAME TYPE VALUE
-------------- ------- -------
disk_asynch_io boolean TRUE
We checked the ASYNC IO inside the DB:
SQL> COL NAME FORMAT A50
SELECT NAME,ASYNCH_IO FROM V$DATAFILE F,V$IOSTAT_FILE I
WHERE F.FILE#=I.FILE_NO
AND FILETYPE_NAME='Data File';
NAME ASYNCH_IO
--------------------------------------------- ---------
+DATAC1/migdb/datafile/system.256.839351447 ASYNC_OFF
+DATAC1/migdb/datafile/sysaux.257.839351449 ASYNC_OFF
+DATAC1/migdb/datafile/undotbs1.258.839351449 ASYNC_OFF
+DATAC1/migdb/datafile/users.259.839351449 ASYNC_OFF
Then we checked the libaio libraries in Linux (they are well):
[root@dm01dbadm01 ~]# rpm -qa|grep libaio
libaio-0.3.106-5
libaio-devel-0.3.106-5
libaio-devel-0.3.106-5
libaio-0.3.106-5
[root@dm01dbadm01 ~]# find / -name libaio*
/usr/lib64/libaio.so.1
/usr/lib64/libaio.so.1.0.0
/usr/lib64/libaio.so.1.0.1
/usr/lib64/libaio.a
/usr/lib64/libaio.so
/usr/lib/libaio.so.1.0.0
/usr/lib/libaio.so.1
/usr/lib/libaio.so.1.0.1
/usr/lib/libaio.a
/usr/lib/libaio.so
/usr/share/doc/libaio-0.3.106
/usr/include/libaio.h
/u01/app/oracle/product/11.2.0.4/dbhome_1/lib/stubs/libaio.so.1
/u01/app/oracle/product/11.2.0.4/dbhome_1/lib/stubs/libaio.so
/u01/app/oracle/product/11.2.0.4/dbhome_1/lib/stubs/libaio-2.3.4-stub.so
/u01/app/11.2.0.4/grid/lib/stubs/libaio.so.1
/u01/app/11.2.0.4/grid/lib/stubs/libaio.so
/u01/app/11.2.0.4/grid/lib/stubs/libaio-2.3.4-stub.so
And the async syscall statistics:
# cat /proc/slabinfo|grep kio
kioctx 86 110 384 10 1 : tunables 54 27 8 : slabdata 11 11 0
kiocb 0 0 256 15 1 : tunables 120 60 8 : slabdata 0 0 0
# more /proc/sys/fs/aio-max-nr
3145728
# more /proc/sys/fs/aio-nr
11008
So, we understand - we loosed the ASYNC IO in the Exadata.
Solution: Patch 16618055 :
The fix Patch 16618055 : PHSB: EXADATA DOESN'T SUPPORT ASYNC I/O is now available for download on top of 11.2.0.4.3
This patch is online installable, we installed it.
In the alert log we see:
Tue Mar 11 13:15:02 2014
Patch bug16618055.pch Installed - Update #1
Patch bug16618055.pch Enabled - Update #2
Tue Mar 11 13:15:05 2014
Online patch bug16618055.pch has been installed
Online patch bug16618055.pch has been enabled
But the DB showed ASYNC_OFF
NAME ASYNCH_IO
--------------------------------------------- ---------
+DATAC1/migdb/datafile/system.256.839351447 ASYNC_OFF
+DATAC1/migdb/datafile/sysaux.257.839351449 ASYNC_OFF
+DATAC1/migdb/datafile/undotbs1.258.839351449 ASYNC_OFF
+DATAC1/migdb/datafile/users.259.839351449 ASYNC_OFF
After shutdown the ASYNC become ON !
calibrate_io (kcfcagmdf): WARNING: ASync I/O not possible for datafile with file number (fno) [1]
calibrate_io (kcfcagmdf): WARNING: ASync I/O not possible for datafile with file number (fno) [2]
calibrate_io (kcfcagmdf): WARNING: ASync I/O not possible for datafile with file number (fno) [3]
calibrate_io (kcfcagmdf): WARNING: ASync I/O not possible for datafile with file number (fno) [4]
We checked the DB parameters:
SQL> show parameter filesystemio
NAME TYPE VALUE
-------------------- ------ ------
filesystemio_options string setall
SQL> show parameter disk_asynch_io
NAME TYPE VALUE
-------------- ------- -------
disk_asynch_io boolean TRUE
We checked the ASYNC IO inside the DB:
SQL> COL NAME FORMAT A50
SELECT NAME,ASYNCH_IO FROM V$DATAFILE F,V$IOSTAT_FILE I
WHERE F.FILE#=I.FILE_NO
AND FILETYPE_NAME='Data File';
NAME ASYNCH_IO
--------------------------------------------- ---------
+DATAC1/migdb/datafile/system.256.839351447 ASYNC_OFF
+DATAC1/migdb/datafile/sysaux.257.839351449 ASYNC_OFF
+DATAC1/migdb/datafile/undotbs1.258.839351449 ASYNC_OFF
+DATAC1/migdb/datafile/users.259.839351449 ASYNC_OFF
Then we checked the libaio libraries in Linux (they are well):
[root@dm01dbadm01 ~]# rpm -qa|grep libaio
libaio-0.3.106-5
libaio-devel-0.3.106-5
libaio-devel-0.3.106-5
libaio-0.3.106-5
[root@dm01dbadm01 ~]# find / -name libaio*
/usr/lib64/libaio.so.1
/usr/lib64/libaio.so.1.0.0
/usr/lib64/libaio.so.1.0.1
/usr/lib64/libaio.a
/usr/lib64/libaio.so
/usr/lib/libaio.so.1.0.0
/usr/lib/libaio.so.1
/usr/lib/libaio.so.1.0.1
/usr/lib/libaio.a
/usr/lib/libaio.so
/usr/share/doc/libaio-0.3.106
/usr/include/libaio.h
/u01/app/oracle/product/11.2.0.4/dbhome_1/lib/stubs/libaio.so.1
/u01/app/oracle/product/11.2.0.4/dbhome_1/lib/stubs/libaio.so
/u01/app/oracle/product/11.2.0.4/dbhome_1/lib/stubs/libaio-2.3.4-stub.so
/u01/app/11.2.0.4/grid/lib/stubs/libaio.so.1
/u01/app/11.2.0.4/grid/lib/stubs/libaio.so
/u01/app/11.2.0.4/grid/lib/stubs/libaio-2.3.4-stub.so
And the async syscall statistics:
# cat /proc/slabinfo|grep kio
kioctx 86 110 384 10 1 : tunables 54 27 8 : slabdata 11 11 0
kiocb 0 0 256 15 1 : tunables 120 60 8 : slabdata 0 0 0
# more /proc/sys/fs/aio-max-nr
3145728
# more /proc/sys/fs/aio-nr
11008
So, we understand - we loosed the ASYNC IO in the Exadata.
Solution: Patch 16618055 :
The fix Patch 16618055 : PHSB: EXADATA DOESN'T SUPPORT ASYNC I/O is now available for download on top of 11.2.0.4.3
This patch is online installable, we installed it.
In the alert log we see:
Tue Mar 11 13:15:02 2014
Patch bug16618055.pch Installed - Update #1
Patch bug16618055.pch Enabled - Update #2
Tue Mar 11 13:15:05 2014
Online patch bug16618055.pch has been installed
Online patch bug16618055.pch has been enabled
But the DB showed ASYNC_OFF
NAME ASYNCH_IO
--------------------------------------------- ---------
+DATAC1/migdb/datafile/system.256.839351447 ASYNC_OFF
+DATAC1/migdb/datafile/sysaux.257.839351449 ASYNC_OFF
+DATAC1/migdb/datafile/undotbs1.258.839351449 ASYNC_OFF
+DATAC1/migdb/datafile/users.259.839351449 ASYNC_OFF
After shutdown the ASYNC become ON !