Originally posted by rameshgiri26
the Oracle Home have not been set on unix environment.

Please set the Oracle_home on unix environment and export it.

then it works.
is this really the root cause? i did a reboot and everything is fine.

If you really do not wish to reboot, you could change the database init.ora parameter disk_asynch_io to FALSE to disable the use of asynchronous I/O within the database. You can simulate Asynchronous I/O by adding DBWRs.
Check this link for details:
http://metalink.oracle.com/metalink...OT&p_id=47328.1
.
However, I would strongly advise you to take advantage of aio and reboot if necessary.
Your questions on aio and rebooting the server are probably better suited to a UNIX forum somwhere.
.
Brgds,
Andy
can u post that note here?