[CentOS] Software RAID and GRUB on CentOS 7

Thu Aug 11 08:27:17 UTC 2016
William A. Mahaffey III <wam at hiwaay.net>

On 08/11/16 02:33, Nicolas Kovacs wrote:
> Hi,
> When I perform a software RAID 1 or RAID 5 installation on a LAN server
> with several hard disks, I wonder if GRUB already gets installed on each
> individual MBR, or if I have to do that manually. On CentOS 5.x and 6.x,
> this had to be done like this:
> # grub
> grub> device (hd0) /dev/sda
> grub> device (hd1) /dev/sdb
> grub> root (hd0,0)
> grub> setup (hd0)
> grub> root (hd1,0)
> grub> setup (hd1)
> grub> quit
> I'd like my server to be able to boot a degraded software RAID after an
> eventual hard disk failure.
> Any suggestions?
> Niki Kovacs

I have an aging FC14 (!!!!) system, w/ mdadm RAID partitions. I have 
/boot setup as mdadm RAID1's, 2 drives (actually partitions). Machine 
boots AOK, & I believe it does (& maintains) that setup automatically. I 
got that recommendation from a mailing list ages ago, can't remember 
where, sorry. $0.02, no more, no less ....

[root at Q6600:/etc, Thu Aug 11, 08:25 AM] 1018 # df -h
Filesystem    Type    Size  Used Avail Use% Mounted on
/dev/md1      ext4    917G  8.0G  863G   1% /
tmpfs        tmpfs    4.0G     0  4.0G   0% /dev/shm
/dev/md0      ext4    186M   60M  117M  34% /boot
/dev/md3      ext4    1.8T  1.4T  333G  81% /home
[root at Q6600:/etc, Thu Aug 11, 08:26 AM] 1019 # uname -a
Linux Q6600 #1 SMP Wed Nov 23 13:07:52 UTC 
2011 x86_64 x86_64 x86_64 GNU/Linux
[root at Q6600:/etc, Thu Aug 11, 08:26 AM] 1020 #


	William A. Mahaffey III


	"The M1 Garand is without doubt the finest implement of war
	 ever devised by man."
                            -- Gen. George S. Patton Jr.