> 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? Based on input from everyone here I am thinking of an alternate setup. Single small inexpensive 64GB SSD used as /boot, / and swap. Putting /vz on software RAID1 array on the two 4TB drives. I can likely just zip tie the SSD in the 1u case somewhere since I have no more drive bays. Does this seem like a better layout?