$ ${bindir:=.}/s4u-io-async ${platfdir}/hosts_with_disks.xml "--log=root.fmt:[%10.6r]%e(%i:%P@%h)%e%m%n"
> [ 0.000000] (1:test@bob) Hello! read 20000000 bytes from Disk1
-> [ 0.000000] (2:test_cancel@alice) Hello! write 50000000 bytes from Disk2
+> [ 0.000000] (2:test_cancel@alice) Hello! write 50000000 bytes from Disk1
> [ 0.200000] (1:test@bob) Goodbye now!
> [ 0.500000] (2:test_cancel@alice) I changed my mind, cancel!
> [ 0.500000] (2:test_cancel@alice) Goodbye now!