Hi all, Please forgive me for my early-morning wonderings, but I am planning to make a non-raid -> raid5 migration in a way that could be summed up like this : Let sda5 be the originial partition. Let sd[bcd]5 be the additionnal ones to build up the raid5. After security backups and sd[bcd]5 partition creation, I would try and do : Step 0 : mdadm -l 5 -n 4 /dev/sd[bcd]5 missing Step 1 : (start the array as degraded) Step 2 : Format /dev/md0, copy sda5 contents to md0, re-create partitions on sda Step 3 : mdadm -a /dev/md0 /dev/sda5 At the end of Step 3, we have a working raid5 4-disk array, with the contents of the previous sda5. My questions are : * When will the (real/final) resync occur ? I guess it's in step3, because during all steps before, there is nothing to resync... Am I right or wrong ? * What happens for real during Step1/2 ? Id est for a given stripe, will the parity block be computed and written as well ? Does a degraded array work exactly as a normal one for blocks layout ? (I can't help wondering, because IHMO, this is a terrific algorithmic issue). Well, having written down my questions I guess I have the answer, so if you just can say 'yes little boy, you're right, md is good for you', I would be pleased. - 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
