On 06/22/2014 10:15 AM, John R Pierce wrote: > so, I installed a c6 system offsite today, had to do it in a hurry. > box has 2 disks meant to be mirrored... I couldn't figure out how to > get anaconda to build a LVM root on a mirror, so I ended up just > installing a /boot and vg_system on sda and raid it later. > > every howto I find for linux says to half-raid the OTHER disk, COPY > everything to it, then boot from it and wipe the first disk and then > bond it as a mirror of the 2nd. Thats kind of ugly. > > in solaris, you can tell it that your existing partition is half of a > mirror, update /etc/vfstab, then reboot, and then join a mirror to it. > this seems much cleaner to me than copying everything. > > I tried to do this the solaris way, and at the first step, am told... > > # mdadm --create /dev/md0 --level=mirror --raid-devices=2 /dev/sda2 > missing > mdadm: cannot open /dev/sda2: Device or resource busy > > > /dev/sda2 contains the LVM root vg... > > so... I'm thinking I''ll boot a rescue system from usb, create the half > mirror, then reboot to the incomplete raid and add mirror /dev/sdb2 > > will the VG be found on /dev/md0 instead of on /dev/sda2 ? > if so, is there any other reason this won't work? > > > This is a best RAID tutorial I saw so far, and I made it better and safer (commands by just copying will fail due to /dev/sdx naming): https://www.facebook.com/notes/centos/software-raid-on-rhel-6/10151254589767728 -- Ljubomir Ljubojevic (Love is in the Air) PL Computers Serbia, Europe StarOS, Mikrotik and CentOS/RHEL/Linux consultant