DTrace to measure ZFS operations & latency

[Michael W. Lucas]

Hi,

I'm working on measuring the number & latency of async operations in
ZFS. (Yes, this is still for the ZFS book.) There's a nice script at
http://dtrace.org/blogs/ahl/2014/08/31/openzfs-tuning/, but it's
illumos-specific. I try to run the script on last week's -current and
get:

# dtrace -s q.d zroot
dtrace: failed to compile script q.d: line 4: probe description fbt::vdev_queue_max_async_writes:entry does not match any probes

Any chance someone could help me out here?

Thanks,
==ml

PS: The script is:

#pragma D option aggpack
#pragma D option quiet

fbt::vdev_queue_max_async_writes:entry
{
        self->spa = args[0];
	}
	fbt::vdev_queue_max_async_writes:return
	/self->spa && self->spa->spa_name == $$1/
	{
	        @ = lquantize(args[1], 0, 30, 1);
		}

tick-1s
{
        printa(@);
	        clear(@);
		}


-- 
Michael W. Lucas  -  mwlucas at michaelwlucas.com, Twitter @mwlauthor 
http://www.MichaelWLucas.com/, http://blather.MichaelWLucas.com/