2011/1/18 Keld JÃrn Simonsen <keld@xxxxxxxxxx>: > On Tue, Jan 18, 2011 at 12:00:49PM -0200, Roberto Spadim wrote: >> like this patch (a long time ago) >> http://www.spinics.net/lists/raid/msg30003.html >> >> >> 2011/1/18 Roberto Spadim <roberto@xxxxxxxxxxxxx>: >> > hi guys, could we implement a load_balance read algorithm for SSD? >> > nearest head isn't as fast as round robin for ssd. >> > i'm talking about raid1 (raid10 too) >> > what's my problem? >> > as i can see, raid0 is faster than raid1 >> > for example: >> > two disks raid0 is faster than >> > two disks raid1. >> > >> > why? >> > nearest head >> > instead of a balanced read algorithm (like raid0) the nearest head >> > make raid1 use only one disk for searchs where we could use two disks >> > (like raid0) >> > >> > could we implement a round robin for ssd? and make raid1 as fast as >> > raid0 for ssd? >> > i didn't tested the raid10 algorithm yet. >> > thanks a lot. > > This should only be in use for SSDs. For disks it would be a waste of IO > bandwidth. How do we detect whether it is a SSSD. > Another way to accomplish an improvement os to use the offset layout of > raid10. > > 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 Âhttp://vger.kernel.org/majordomo-info.html > Hi, There is a way to check if the device is an SSD or not; the rotational queue flag in sysfs. See http://amailbox.org/mailarchive/git-commits-head/2009/1/30/4859834/thread . // Mathias -- 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
