search for: ncq_performance_analysi

I''ve been looking into the performance impact of NCQ. Here''s what i found out: http://blogs.sun.com/erickustarz/entry/ncq_performance_analysis Curiously, there''s not too much performance data on NCQ available via a google search ... enjoy, eric

fun example that shows NCQ lowers wait and %w, but doesn''t have much impact on final speed. [scrubbing, devs reordered for clarity] extended device statistics device r/s w/s kr/s kw/s wait actv svc_t %w %b sd2 454.7 0.0 47168.0 0.0 0.0 5.7 12.6 0 74 sd4 440.7 0.0 45825.9 0.0 0.0 5.5 12.4 0 78 sd6 445.7 0.0

First Post! Sorry, I had to get that out of the way to break the ice... I was wondering if it makes sense to zone ZFS pools by disk slice, and if it makes a difference with RAIDZ. As I''m sure we''re all aware, the end of a drive is half as fast as the beginning ([i]where the zoning stipulates that the physical outside is the beginning and going towards the spindle increases hex