I've had intermittent server problems of extreme slowness accessing
files all day. Server reboot didn't help it.

Unfortunately I remembered what is the most likely cause after I started
a pool rebuild. It's a 3TB volume that after an hour is only 5% done

356 System objects per sec
79 Disk blocks read per sec
39 disk blocks written per sec

As I recall last time power cycling the enternal rain unit resolved this
issue. Unfortunately I already started the rebuild and at this rate I
can see it taking a day to complete if not more.

Am I totally out of luck at this point until it finishes?