If you accidentally started a scrub on a pool or need to stop one for any reason it’s fortunately quite straightforward:
# zpool scrub -s [poolname]
e.g. zpool scrub -s kepler
You can check on whether that was successful with zpool status – it will give an output above the pool status that looks like:
scan: scrub canceled on Sat Sep 29 10:30:14 2012
Unnecessary scrubbing just wastes power – particularly for a large, nearly-full array where you’ll have quite a few disks running constantly for hours – so it’s good practice to cancel an accidentally-started scrub.