nalarm=value
and noprogt=value options useful to detect slow or no I/O times, esp. during failovers.
nalarm()
generates SIGALRM signal which can only be delivered during interruptible kernel sleeps, thus it’s not always
sent.
n
nExample:
ushaix11# ./dt of=/dev/rhdisk7 bs=64k aios=16 pattern=iot \
u alarm=3s noprogt=15s runtime=5m
stats=brief
u[ Initiated controller takeover to force path failover.
]
udt: No progress made for 18 seconds!
udt: No progress made for 21 seconds!
u ...
udt: No progress made for 39 seconds!
u