On Fri, Jan 24, 2014 at 11:58 AM, Matt <matt.mailinglists@xxxxxxxxx> wrote:
> I installed Centos 6.x 64 bit with the minimal ISO and used two disks
> in RAID 1 array.
>
> Filesystem Size Used Avail Use% Mounted on
> /dev/md2 97G 918M 91G 1% /
> tmpfs 16G 0 16G 0% /dev/shm
> /dev/md1 485M 54M 407M 12% /boot
> /dev/md3 3.4T 198M 3.2T 1% /vz
>
> Personalities : [raid1]
> md1 : active raid1 sda1[0] sdb1[1]
> 511936 blocks super 1.0 [2/2] [UU]
> md3 : active raid1 sda4[0] sdb4[1]
> 3672901440 blocks super 1.1 [2/2] [UU]
> bitmap: 0/28 pages [0KB], 65536KB chunk
> md2 : active raid1 sdb3[1] sda3[0]
> 102334336 blocks super 1.1 [2/2] [UU]
> bitmap: 0/1 pages [0KB], 65536KB chunk
> md0 : active raid1 sdb2[1] sda2[0]
> 131006336 blocks super 1.1 [2/2] [UU]
>
> My question is if sda one fails will it still boot on sdb? Did the
> install process write the boot sector on both disks or just sda? How
> do I check and if its not on sdb how do I copy it there?
>
I've found that the grub boot loader is only installed on the first disk.
When I do use software raid, I have made a habit of manually installing
grub on the other disks (using grub-install). In most cases I dedicated a
RAID1 array to the host OS and have a separate array for storage.
You can check to see that a boot loader is present with `file`.
~]# file -s /dev/sda
/dev/sda: x86 boot sector; partition 1: ID=0xfd, active, starthead 1,
startsector 63, 224847 sectors; partition 2: ID=0xfd, starthead 0,
startsector 224910, 4016250 sectors; partition 3: ID=0xfd, starthead 0,
startsector 4241160, 66878595 sectors, code offset 0x48
There are other ways to verify the boot loader is present, but that's the
one I remember off the top of my head.
Use grub-install to install grub to the MBR of the other disk.
> _______________________________________________
> CentOS mailing list
> CentOS@xxxxxxxxxx
> http://lists.centos.org/mailman/listinfo/centos
>
--
---~~.~~---
Mike
// SilverTip257 //
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
http://lists.centos.org/mailman/listinfo/centos
