So I'm trying to RAID-1 this system which has two identical disks installed in it, and it isn't working for some reason. I started by doing a CentOS-4 install on /dev/sda1 as root, and with /dev/sda2 as my swap. I finish the install, yum update, and then I want to make the mirrors. I copy the partition table from one disk to the other: # sfdisk -d /dev/sda | sfdisk /dev/sdb I create my metadevices: # mdadm -Cv -l1 -n2 /dev/md1 /dev/sdb1 missing # mdadm -Cv -l1 -n2 /dev/md2 /dev/sdb2 missing I create my filesystems: # mkfs.ext3 /dev/md1 # mkswap /dev/md2 I change the /etc/fstab to use /dev/md1 for / and /dev/md2 for swap. I change the /etc/grub.conf to use /dev/md1 for the root= parameter on my kernel. I build myself a new initrd for the kernel I want to boot. I copy the contents of / over to the one-armed mirror: # cd / # mnt /dev/md1 /mnt/md1 # tar cfpl - . | ( cd /mnt/md1 ; tar xfp -) # umount /mnt/md1 # sync I run grub just in case: # grub > device (hd0) /dev/sda > root (hd0,0) > setup (hd0) I reboot, expecting that the system will find /dev/md1 and use it as its root... but it doesn't. Digging around in hobbled mode (changing the root= parameter in grub to /dev/sda1 instead of /dev/md1) shows that /dev/md1 doesn't get assembled, therefore it doesn't get mounted. Can anyone tell me what I've done wrong? -- /\oo/\ / /()\ \ David Mackintosh | dave at xdroop.com | http://www.xdroop.com -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: not available URL: <http://lists.centos.org/pipermail/centos/attachments/20070925/567685d2/attachment-0004.sig>