recall that it has been added with Wheezy. But let me put forward
that it doesn't really matter. If you have RAID then you know you
want grub on both disks. After installing simply run the grub install
script against both disks manually and then you will be assured that
it has been installed on both disks.
I had problems with that methodology and was unable to detect my error. From a thread on debian dated Mar 2, 2013:
I carried out a reinstall of amd64 wheezy
on the machine with new HD. md0 (boot, ext20, md1 (LVM, home, usr,
etc). GRUB came installed on /dev/sda only
Then the command
grub-install /dev/sdb
was reported by complete installation. No error, no warning.
On rebooting, GRUB was no more found. Then entering in
grub rescue >
prefix/root/ were now wrong.
Now I am in the same situation, two servers with mirroring raid, grub on /dev/sda only. Identical data on both servers to cope with grub on one disk only. Not smart from my side.
I agree with the other responder. It is unlikely IMNHO that you want
RAID0 (striping) for the system disk. You most likely want RAID1
(mirroring) instead. The answer above is the same regardless. If you
are thinking striping for performance instead I recommend using an SSD
for the system disk.
Ah! my mistake. Sure, raid1 (mirroring)
thanks
francesco