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I have a Dell Dimesion 8200 with (2) 40Gb drives. I installed Fedora Core and I want to create "RAID 1" partitions for "/" , "/boot", and "/usr". I was following documentation from the Red Hat site (Chapter 12 RH Enterprise 3 Sys Admin Guide) and it looked to be working because it copied from the CD to the hard drives. Finally it displayed "Loading Boot Loader" and it sat there for 3-5 minutes. Then I got a "Congratulations ... Fedore Install completed" message and it started rebooting. It displayed the word "GRUB" on an empty screen and sat there. I could not CTL/ALT/DLT so I powered it off and then back on and again it stopped at "GRUB" on an empty screen.
I selected "GRUB" as the BOOT LOADER during the install because that is all I have ever selected doing a Linux install. However, this is my 1st RAID install and I don't know what I did wrong. Possibly I need to use LILO?
cbriscoejr: There is nothing really special about using Grub with Linux Software Raid 1, as long as it points to the first disk of the Raid 1 pair. If you changed the Raid drive order during the partition setup, that could trigger an outright Grub problem, but that could be easily fixed by reinstalling Grub.
There may be something odd going on in either /boot/grub/grub.conf or /etc/fstab. Boot into linux rescue and have a look at grub.conf and fstab to make sure that /dev/md0, 1 and 2 are being correctly used. As a side point, you sometimes have to skip the search for existing installations in linux rescue and just manually mount the partitions so that you can look inside.
cbriscoejr: Sounds like something got messed up during the installation, given what you found in fstab. The absence of /dev/md0 is perplexing, to say the least. What you did during the installation sounds right.
You could try inserting the correct fstab entries and see if it boots. Instead of the traditional LABEL= or /dev/hdxy setup, use /dev/md0, /dev/md1 and /dev/md2. Things may be bad enough that you should just reinstall and use the first setup as a learning experience.
A good piece of advice I read in this forum about using Linux Software Raid was to do several small installations using different setups to learn both how it works and what works best for you. I did 5 or 6 installations/reinstallations the first day as Raid 0/1/5 and learned a lot. I wanted to try Raid6 (2-dimensional Raid5), but I don’t have a system that would run it.
For Grub help, look in the Grub manual (www.gnu.org/software/grub/manual/grub.html), paying close attention to the sections “Installing GRUB using grub-install”, “Installing GRUB natively” (i.e., using the Grub commands “find ...”, “root ...” and “setup ...”) and, when all else fails, “Creating a GRUB boot floppy” or “Making a GRUB bootable CD-ROM”. Grub is installed on your hard disk(s) and can be accessed by running “linux rescue” and mounting the installation. It should also be available on bootable CD distributions like Knoppix, which is kernel 2.4-based (http://www.knopper.net/knoppix/index-en.html).
"If you are making a RAID partition of /boot, you must choose RAID level 1, and it must use one of the first two drives (IDE first, SCSI second). If you are not creating a RAID partition of /boot, and you are making a RAID partition of /, it must be RAID level 1 and it must use one of the first two drives (IDE first, SCSI second)."
I made both "/" and "/boot" RAID 1. I only have the 2 IDE drives. Do you what I have done as being within this statement?
Yeah, that was OK. Grub cannot open Raid0 or Raid5 partitions, but a Raid1 partition looks “normal” to it. The FC3 installation utility for setting Raid partitions has a failsafe built in and will not let you make a mistake assigning the boot partition Raid type. If/when you reinstall the Raid setup, intentionally try to improperly configure /boot as Raid0 and it will immediately reject the configuration with a very explicit warning message.
Also, since you are doing Raid1 across the board, check out the “clone disk” feature while setting up the Raid partitions. BTW, both disks can have a swap partition treated as a Raid0 partition. Look at the “Swapping on RAID” (default,pri=1) section in the How-To I referenced for details.
I can't clone because the drives are not the same size. All this was using IDE. I have a 3 SCSI installs that I have to do also. The SCSI installs will have 3 drives. All the same size. What is the best scenario for Raid? I can't just raid 5 all of it because / and /boot have to be raid 1.
You may have misunderstood the restriction regarding /boot being Raid1. If /boot is NOT in the same partition as “/”, then “/” can be Raid whatever-you-want-it-to-be. If /boot is in the “/” partition, then the Raid1 restriction applies to the “/” partition, but only because it contains /boot.
The deal is that the boot loaders are not smart enough (read: don’t have enough drivers) to open Raid0 and Raid5 partitions, so the /boot-containing partition either has to be a non-Raid or Raid1 partition, where a Raid1 partition looks, acts, smells and tastes like a non-Raid partition. Using Linux Software Raid is the only reason I ever create a separate /boot partition, so that everything else can either be Raid0 or Raid5, depending on the number of drives available.
So to summarize for 3 SCSI drives: Make /boot Raid1, make / and /anything-else-you-want-to-slit-out Raid5. And don’t worry, the setup utility will not let you do it incorrectly anyway.
And about the cloning, as long as the partitions do not exceed the size of the target drive, you can clone partition from one drive to the other, regardless of their relative sizes. Or said another way, if you fill up the smaller drive with partitions, then you can clone them to the bigger drive.