Scott Silva wrote:
If you have a disk with several partitions set up as members of a raid1 md devices, can you make a dd image of that disk to replace its matching drive with identical partitions or are there differences between the mirrored partitions?
you can 'dd' the MBR and then re-add the partitions to the raid for resyncing with 'mdadm'.
# dd if=/dev/sda of=/dev/sdb bs=512 count=1 # mdadm /dev/md0 --add /dev/sdb1 # mdadm /dev/md1 --add /dev/sdb2
If you want to really make sure you got everything you could dd the whole first track with:
# dd if=/dev/sda of=/dev/sdb bs=512 count=63
-Ross
Or sfdisk -d /dev/sdX | sfdisk /dev/sdY where x is source and y is the target. This will work across drives that have slight geometry differences.
What I was hoping to do was to take the grub setup, the partitioning info and the contents in one shot and have the disks pair automatically when booted. They didn't - but I think the other parts worked.
Now, is there a way to change the uuid on a running raid1 set? I'd prefer that if the split and re-paired disks ever find their way back to the same machine that they not sync again.