--On Wednesday, September 07, 2011 08:22:47 PM +0300 Bünyamin İzzet <bunyamin.izzet at gmail.com> wrote: > Hello, > > I have two disks sda and sdb. One of the was broken so I have changed the > broken disk with a working one. I started the server in rescue mode, and > created the partional table, and added all the partitions to the software > raid. Sounds like the 'no boot record' issue. Here's an extract from one of my server change logs, for setting things up *before* they go bad: - made sure we have boot blocks on both disks, based on information at http://grub.enbug.org/MirroringRAID modified /boot/grub/device.map from: (hd0) /dev/sda (hd1) /dev/sdb to: (hd0) /dev/sda (hd0) /dev/sdb and then: # grub grub> device (hd0) /dev/sdb grub> root (hd0,0) grub> setup (hd0) grub> quit With the above in place you can boot from either disk as long as your BIOS will let you select the boot device. I've had older systems where the BIOS didn't have that option, in which case the 'in event of breakage' procedure would be to take the working slave disk and put it on the controller cable that originally had the flawed master disk. ># cat /boot/grub/device.map > (hd0) /dev/sda > (hd1) /dev/sdb Not quite right (need hd0 on both) Devin