On Tue, Jun 28, 2016 at 02:25:02PM +0500, Roman Mamedov wrote: > On Sun, 26 Jun 2016 13:34:05 -0400 > Phil Turmel <philip@xxxxxxxxxx> wrote: > > > On 06/26/2016 01:20 PM, Paul Roland wrote: > > > > > I have two SSDs, and I would like to use md/raid10 (2devices) for > > > performance reasons. > > > > Ok, that's reasonable. > > Maybe I'm missing something, but how is a RAID10 of just two devices is > considered reasonable without any questions or explanation? What is the actual > layout that is expected here, and what benefits (or even differences) does it > have compared to RAID0? I thought you need at least 3 devices (and h/w RAID > controllers might even require 4) for RAID10 to start making sense. I think your understanding is a common misunderstanding of the Linux raid10. There is more on this subject on: https://en.wikipedia.org/wiki/Non-standard_RAID_levels#Linux_MD_RAID_10 In short: yes Linux MD RAID10 is a different beast than standard RAID 1+0, It can work with improved performance with just 2 disks, and even perform like RAID0 for the Linux MD RAID10 far layout See more on https://raid.wiki.kernel.org/index.php/Performance 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
