I created a new array after upgrading kernel and OS (2.6.32.25-cracauer and Debian/squeeze, respectively, resulting in mdadm - v3.1.4 - 31st August 2010) The new array reads md0 : active raid5 sdc2[4] sda2[2] sdb2[1] sdd2[0] 292998144 blocks super 1.2 level 5, 256k chunk, algorithm 2 [4/4] [UUUU] I figure the "super 1.2" means the new version of the superblock. Can I read that array if I ever connect the machine to an older kernel/mdadm? I see that I can control which version to use in mdadm(8), but I don't get what the advantage of the new format is if I don't run out of # of components or total capacity. I can see how storing the superblock at 4 KB makes it more robust against accidents that wipe out of the first 512 bytes or similar fun. I think storing it at the end will be a pain if you ever have to hexdump recover the thing, no? I also wonder why this is the only version announced in /proc/mdstat if it is what is now the default? Shouldn't it announce the v0.9 blocks? Is anybody here using the DDF format? I don't plan to get hardware raid but why not prepare for it? Thanks Martin -- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Martin Cracauer <cracauer@xxxxxxxx> http://www.cons.org/cracauer/ -- 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