On Thu, May 23, 2013 at 10:45:56PM -0500, Stan Hoeppner wrote: > On 5/23/2013 3:30 AM, keld@xxxxxxxxxx wrote: > > On Thu, May 23, 2013 at 12:59:39AM -0500, Stan Hoeppner wrote: > > >> You may be tempted to use md/RAID10 of some layout > >> to optimize for writes, but you'd gain nothing, and you'd lose some > >> performance due to overhead. The partitions you'll be using in this > >> case are so small that they easily fit in a single physical disk track, > >> thus no head movement is required to seek between sectors, only rotation > >> of the platter. > ... > > I think a raid10,far3 is a good choice for swap, then you will enjoy > > RAID0-like reading speed. and good write speed (compared to raid6), > > and a chance of live surviving if just one drive keeps functioning. > > As I mention above, none of the md/RAID10 layouts will yield any added > performance benefit for swap partitions. And I state the reason why. > If you think about this for a moment you should reach the same conclusion. I think it is you who are not fully aquainted with Linux MD. Linux MD RAID10,far3 offers improved performance in single read, which is an advantage for swap, when you are swapping in. Thinkk about it and try it out for yourself. Especially if we are talking 3 drives (far3), but also when you are talking more drives and only 2 copies. You don't get raid0 read performance in Linux on a combination of raid1 and raid0. best regards keld -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
