I'm not sure if this is weird raid, stupid grub2 or incompetent newbie, but whatever ... and the system is my development/test system so if it gets trashed it's no disaster, but I would like to understand what is going on ... Old setup / = sdb2 /var = sdc2 /home = mdX (sdb3, sdc3), mirror I added sdd and made a new / = mdY (sdd3, missing) mirror and added sdd4 to mdX /home = mdX (sdb3 sdc3 sdd4) Weirdo one - sdd4 mirrored and synced fine. Then I rebooted ... mdX = (sdb3 sdc3 missing) mdZ = (sdd4 missing missing) wtf?!?!? - oh and both of them share the same uuid. The obvious (but it shouldn't make any difference?) possibility is that sdb and sdc are 500Gb, partitioned identically. sdd is 1Tb, so sdd4 is twice the size of the other two. The other weirdo is I'm trying to migrate from grub/mbr to grub2/gpt. Of course that's causing me fun, but I've managed to get the system booting fine from mdY. Only snag is, when I list /dev, mdY isn't there! mount shows it as mounted on / but that's the only place I can find it! mdadm v3.2.6 kernel 3.14.14-gentoo Any ideas what's going on? I've googled, but everything I find looks out of date or not relevant. Cheers, Wol -- 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