Ask The Real Tom

I tried to run IO calibrate to check what the system is able to handle.
But I run into following error (using ASM / ASMlib)


ORA-56708: Could not find any datafiles with asynchronous i/o capability
ORA-06512: at "SYS.DBMS_RMIN", line 456
ORA-06512: at "SYS.DBMS_RESOURCE_MANAGER", line 1285
ORA-06512: at line 6


The ASM files show ASYNC_ON

SELECT name, asynch_io
FROM v$datafile f,v$iostat_file i
WHERE f.file# = i.file_no
AND filetype_name = 'Data File'
/
+DG1/xxxx/datafile/system.260.721649043
ASYNC_ON
....


did not help as well

alter system set filesystemio_options=setall scope=spfile;
shutdown immediate
startup


I guess that the problem is that moste datafiles (smallfiles) are full (max. number of blocks). So the io calibrate tool can not write to this files.

System aio slots:

To find out the maximum avalable asynch I/O slots:
$ cat /proc/sys/fs/aio-max-nr
65536

To find out how many are being used:
$ cat /proc/sys/fs/aio-nr

increase fs.aio-max-nr if nessesary (or restart some db's)
65536