nReport no or slow
I/O progress
ucan disable timing individual system calls
nRetries data
corruptions
ufor file systems via Direct I/O (DIO)
umay also loop on corruption with interval
nHistory for
recording I/O’s
udata bytes saved
uoptionally with timing
nLog test info/errors
to system logger
nReport periodic
statistics via keepalive
nTrigger mechanism
for troubleshooting