I just want to do this: Now there is 4 hard disks, to build RAID1 on RAID0.
I splite the partitions of every disk to 2 part: the system part and data part. data part will be build RAID1 on RAID0, and system part, to make the system always availabe, I build only RAID1 for disk partitions: /(sda1,sdb1,sdc1 & sdd1), /usr(sda2,sdb2,sdc2,sdd2).
Then I must setup grub on all these 4 disks to make the system can boot up from anyone when the previous disk is broken, so do this:
grub> install (hd0,0)/boot/grub/stage1 d (hd1) (hd0,0)/boot/grub/stage2 p (hd0,0)/boot/grub/grub.conf
grub> install (hd0,0)/boot/grub/stage1 d (hd2) (hd0,0)/boot/grub/stage2 p (hd0,0)/boot/grub/grub.conf
Now if I remove sda, the system can boot from sdb, GRUB works well. But then I go on remove sdb, I just get a command prompt of grub while boot:
If I run the right commands, I can boot the system:
grub> root (hd0,0)
grub> kernel /boot/vmlinuz-VERSTION ro root=/dev/md0
grub> initrd /boot/initrd-VERSTION.img
But I don't think it's convenience, what is the problem and what is the solution?