On Thu, July 9, 2009 6:36 pm, Mikael Abrahamsson wrote: > On Wed, 24 Jun 2009, Beolach wrote: > >> If a raid5 is changed to raid6, and then the raid6 is grown w/ >> additional disks, will that switch it to a more traditional layout, >> since it has to be re-striped anyway? > > I'd greatly appreciate if someone in the know could answer this? Sorry, I thought I had... must have only intended to. The answer is "only if you explicitly tell it to", which mdadm-3.1 will do for you. If you switch to raid6 by writing to a sysfs file, then grow with an earlier version of mdadm, it will keep to unusual layout. > > Also, this raid6 with all Q blocks on a single drive, will older kernels > read this as well or is 2.6.30 needed to handle this "new" layout? You will need 2.6.30. Older kernels will not understand it. > > I'd like to convert a raid5 to raid6 with 2.6.30, then go back to 2.6.28 > and run it, then when I grow it next time, I'd like to get the "correct" > layout with the Q blocks striped just as if I had created the raid6 from > scratch. Is this possible? Nope, sorry. NeilBrown -- 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
