ORA-27061: skgfospo: waiting for async I/Os failed

Database crashes producing ORA-27061 [ID 452866.1]
 
ORA-27061: skgfospo: waiting for async I/Os failed
IBM AIX RISC System/6000 Error: 22: Invalid argument



The problem is always encountered by the DBWR processes by AIX BUG FOR 5.3.0.60 or 5.3.0.61 level :
IZ03260: LIO_LISTIO FAILS TO UPDATE AIO CONTROL BLOCKS ON ERROR
http://www-1.ibm.com/support/docview.wss?uid=isg1IZ03260

Solution:
1. Increase the max limit for AIO requests (maxreqs) using the chdev command.
chdev -l aio0 -a maxreqs=
 
2.Or Install Fix APAR IZ03260 ( for aix )

3. As a workaround, DBWR IO slaves can be increased to handle the IO workload. However, this is an issue that need to get addressed to the hardware vendor (IBM) to check driver and I/O system.
alter system set DBWR_IO_SLAVES = 4 scope=spfile;