----- Original Message ----- From: "Mark Milhollan" <mlm at pixelgate.net> To: "Jeff Boyce" <jboyce at meridianenv.com> Sent: Thursday, December 04, 2014 7:18 AM Subject: Re: [CentOS] CentOS 7 install software Raid on large drives error > On Wed, 3 Dec 2014, Jeff Boyce wrote: > >>I am trying to install CentOS 7 into a new Dell Precision 3610. I have >>two 3 >>TB drives that I want to setup in software RAID1. I followed the guide >>here >>for my install as it looked fairly detailed and complete >>(http://www.ictdude.com/howto/install-centos-7-software-raid-lvm/). > > I suggest using the install guide rather than random crud. The storage > admin guide is fine to read too, but go back to the install guide when > installing. > > > /mark > Well I thought I had found a decent guide that wasn't random crud, but I can see now that it was incomplete. I have read the RHEL installation guide (several times now) and I am still not quite sure that it has all the knowledge I am looking for. I have played around with the automated and the manual disk partitioning system in the installation GUI numerous times now trying to understand what it is doing, or more accurately, how it responds to what I am doing. I have made a couple of observations. 1. The installer requires that I have separate partitions for both /boot and /boot/efi. And it appears that I have to have both of these, not just one of them. 2. The /boot partition can not reside on LVM. 3. The options within the installer then appear to allow me to create my LVM with Raid1, but the /boot and /boot/efi are then outside the Raid. 4. It looks like I can set the /boot partition to be Raid1, but then it is a separate Raid1 from the LVM Raid1 on the rest of the disk. Resulting in two separate Raid1s; a small Raid1 for /boot and a much larger Raid1 for the LVM volume group. I finally manually setup a base partition structure using GParted that allowed the install to complete using the format below. sda (3TB) sda1 /boot fat32 500MB sda2 /boot/efi fat32 500MB sdb (3TB) sdb1 /boot fat32 500MB sdb2 /boot/efi fat32 500MB The remaining space was left unpartitioned in GParted, which was then prepared as LVM Raid1 in the CentOS installer. The installer also put the /boot and /boot/efi files on sda1 and sda2. Then I would have to manually copy them over to sdb1 and sdb2 if I wanted to be able to boot from drive sdb if drive sda failed. I am not sure that this result is what I really want, as it doesn't Raid my entire drives. The structure below is what I believe I want to have. sda & sdb RAID1 to produce md1 md1 partitioned md1a /boot non-LVM md1b /boot/efi non-LVM md1c-f LVM containing /, /var, /home, and /swap Well the abbreviations may not be the proper syntax, but you probably get the idea of where I am going. If this is correct, then it looks like I need to create the RAID from the command line of a rescue disk and set the /boot and /boot/efi partitions first before beginning the installer. But then again I could be totally off the mark here so I am looking for someone to set me straight. Thanks. Jeff