Please, can anyone help out with this problem. Can anyone think of a possible reason why the UUID changed? No command was run that I can imagine would change the UUID. The only thing that I could see that possibly could change the UUID is adding a partition that had previously been part of another partition, without zeroing the superblock first. Also can anyone see why the system wouldnt boot without the original /dev/sdb? The /dev/sdb that replaced it had no partitions created on it, it was brand new. Could that cause a problem? And then why it then wouldnt boot with the original /dev/sdb? Any guess, hypothesis will do, I need some ideas to investigate and find out what happened and I have drawn a blank. Or am I asking in the wrong mailing list, if so can somebody tell me the correct mailing list to use. Thanks Andy Bailey -- 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