I have the following RAID 1 on a Centos 6.5 server:
# cat /proc/mdstat Personalities : [raid1] md0 : active raid1 sdb1 974713720 blocks super 1.0 [2/1] [_U] bitmap: 7/8 pages [28KB], 65536KB chunk md1 : active raid1 sdb2 sda2 2045944 blocks super 1.1 [2/2] [UU] unused devices: <none> # df -h Sist. Arq. Size Used Avail Use% Montado em /dev/md0 915G 450G 420G 52% / tmpfs 7,8G 0 7,8G 0% /dev/shm
/dev/sda is about to fail. I even marked it as faulty since it was causing read errors.
I got the new HD today which will replace /dev/sda.
The issue is that when I unplug the current /dev/sda, I can't make it boot only with /dev/sdb. It looks like the PC's BIOS can't find anything bootable on /dev/sdb.
1) How can I detect if grub is installed in /dev/sdb's MBR?
2) Is it safe to run grub-install in /dev/sdb? Is this the correct way of making it bootable?