On Thursday March 1, jpiszcz@xxxxxxxxxxxxxxx wrote: > You can only grow a RAID5 array in Linux as of 2.6.20 AFAIK. There are two dimensions for growth. You can increase the amount of each device that is used, or you can increase the number of devices. You are correct that increasing the number of devices only works for RAID5 (and RAID1, but you don't get extra space) in 2.6.20 (RAID6 coming in 2.6.21). However this question is about growing an array the first way: increasing the amount of space used on each devices, and that is supported for RAID1/4/5/6. And Laurent: 1/ Yes, it is that easy 2/ I doubt a nearly-full ext3 array increases the risk 3/ The effect of adding a bitmap is that if you suffer a crash while the array is degraded, it will resync faster so you have less exposure to multiple failure. 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