Stakanov -- ...and then Stakanov said... % % Situation: % I have a 2 GB disc mounted as /var/lib/libvirt/images. ... % So I took a second one, same size to set up a RAID1 % ... % % So I want to create a RAID called md/1 and use it as RAID setting it up with % one "missing". dev/sdd is the one with the data. /dev/sdf is the virgin new. % % I began with: % dd if=/dev/sdd of=/dev/sdf count=1 Why are you bothering with this? First, you have no particular reason to duplicate the partition table. Second, you should be using something like sgdisk --backup or sfdisk -d to dump the table if that's what you really wanted to do (which, again, I think it isn't here). Personally, I like to make a partition of almost the entire disk for my RAIDed content and then leave a tiny slice at the end where I write data about the disk and RAID set. I even go so far as to format each disk's tiny slice with different filesystems, but that's just me :-) Whether you use a partition or the whole device, though, it's simple enough just to set that up manually with fdisk or gpt rather than duplicating something that wasn't meant to hold RAID content in the first place. ... % % Now I wish to give it a file system (in my case ext4) and there...the trouble % begin. I do not remember obviously how to do this right. I tried: % mkfs.ext4 /dev/md/1 [snip] Most folks prefer to create a valid partition table on the new device and then put a filesystem on that. Try something like fdisk /dev/md/1 to set up your partitions and then mkfs.ext4 /dev/md/1p1 to create a filesystem on the new partition. [Actual results may vary, of course; do not just mouse-n-paste :-] Good luck! :-D -- David T-G See http://justpickone.org/davidtg/email/ See http://justpickone.org/davidtg/tofu.txt