Bob Friesenhahn <bfrie...@simple.dallas.tx.us> writes: > On Sat, 10 Apr 2010, Harry Putnam wrote: > >>>> Am I way wrong on this, and further I'm curious if it would make more >>>> versatile use of the space if I were to put the mirrored pairs into >>>> one big pool containing 3 mirrored pairs (6 discs) >>> >>> Besides more versatile use of the space, you would get 3X the >>> performance. >> >> That speed up surprises me. Can you explain briefly how that works? > > It is quite simple. With three sets of mirrors in the pool, the data > is distributed across the three mirrors. There is 3X the hardware > available for each write. There is more than 3X the hardware for each > read since either side of a mirror may be used to satisfy a read.
Thanks for your comments. Its always so much easier when someone explains in plain english. >> If that is a bit much to ask here, maybe a pointer to specific >> documentation? > > That would be too much to ask since it is clear that you did not spend > more than a few minutes reading the documentation. Spend some more > minutes. Well now, that would only be true if you meant very recently. In fact I have spent quite hefty amounts of times reading zfs and opensolaris documentation. Including hefty tracts of the `Bible' (that isn't even close) book. The trouble is that I'm understand about 1/10 of it, and that 1/10 soon departs my pea brain when I don't use it daily. You may be used to dealing with folks who have a basic understanding of OSs' and programming, rc files and etc. Probably some amount of formal higher education too. I've come on that kind of info in a very haphazard, hard scrabble way. My education stopped in 9th grade, I went to work at that point, out in the west of our country. Started industrial work a few yrs later (1965) and eventually became a field construction boilermaker and worked around many of the midwest, western and west coast states on refineries, powerplants, steelmills, and other big industrial plants (now retired). None of that was very conducive to the finer points of Operating systems and programming or admin chores. So whatever I've learned about that kind of stuff in the last 10 yrs or so has gaping holes that you could drive 18 wheelers through. I've never found that reading documentation I barely understand is a very good way of actually learning something. On the other hand, hearing about it from current practitioners and heavy experimentation is (for me) the best way to learn about something. With some of that going, then the documentation may start to be a lot more meaningful, once I have something to hang it on. Egad... sorry about the rant but sometimes it seems to just need to be said. Thanks again for what you have contributed, not just to this thread but your many hundreds, maybe thousands of messages of help to others as well. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
