I'am running CentOS 4.3 on an (Intel) with one SATA disk (/dev/sda). The output of fdisk -l: Disk /dev/sda: 81.9 GB, 81964302336 bytes 255 heads, 63 sectors/track, 9964 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 19 152586 83 Linux /dev/sda2 20 2569 20482875 83 Linux /dev/sda3 2570 2700 1052257+ 82 Linux swap /dev/sda4 2701 9964 58348080 5 Extended /dev/sda5 2701 9964 58348048+ 83 Linux So, I have an identical second disk (sdb) connected... My question is: How can I build a RAID 1 of all my particions of sda using mdadm? Something like this: /dev/md0 --> /dev/sda1 and /dev/sdb1 /dev/md1 --> /dev/sda2 and /dev/sdb2 /dev/md2 --> /dev/sda5 and /dev/sdb5 Regards Israel