check the permission. Its ok. sybase has privilege on async i/o device. Our devices are all on raw partition.DB server will use 1 gb while startup. Free physical memory is only 850 mb , but it is coming up with standard unix io in primary server but while coming up in failover server it is hanging.
Any tracing would have very little impact in diagnozing the problem. Sybase simply makes calls to the OS resource, and for whatever reason that it fails is reported back to the errorlog. I doubt any tracing that would throw anything extra. What you really need is some sort of async driver debugger to trace at the async driver what is happening.