I was wondering if anyone knows how or if it is possable to install FreeBSD on two IDE drives that are mirrored? I have a Cobalt RAQNas that has Cobalts version of RedHat Linux installed on two mirrored drives so I wondered if I could do this with FreeBSD? I know you can use CCD to make software RAID 1 drives but can you have the primary operating system running on them?

Don't use ccd (unless you're running 2.2.x); use vinum(8) (www.vinumvm.org).

The root partition can't be mirrored (right now, they're working on that) due to issues with the boot loader; however, everything else can be mirrored, which gives you 99% of the benefit. (You shouldn't be writing to the root partition much at all, so any faliure there is probably a hardware issue; and if your boot drive dies completely then software RAID is never going to help you).

Thank you for the information. A found some other documentation that supports that also. So I will use my 4.3 GB drive for "/" root and two 20GB drives in RAID mirror for /usr :)

You can do that if you want, but it isn't necessary. The software RAID works at a level between partitions and labels, so you could easily use just the two 20GB drives, creating a 100MB / on one drive, a 100MB /mnt/root on the other, and splitting the remaining space on each drive into RAID 1 plexes.

The fact that the root partition can't be RAIDed doesn't imply that it can't be on the same drive as stuff which is RAIDed.

<edit>To put it another way which might make more sense, software RAID isn't restricted to doing entire drives the way hardware RAID is, so you can put / on one drive and use RAID for the rest of the drive.</edit>

So if I wanted to use the two drives in Raid 1, would I install FreeBSD on drive one. Then use "vinum" to have /usr mirrored with the other drive?
I will read more into vinum(8). :)

sysinstall is aware of vinum, so you can set up vinum during the initial install process. Which is probably a good idea... vinum's command line configuration is arcane at best, and most people suggest using sysinstall to set up vinum slices even after the initial install.

VINUM is the best way to go, if you have to do
software raid... probably only best to be used
on data drives.

But, if you are serious about raid, go hardware
raid, much more reliable IMO.

Originally posted by mrjaytee
But, if you are serious about raid, go hardware
raid, much more reliable IMO.

Much more reliable? I'd dispute that. vinum is a very well designed piece of code, and I haven't yet heard of any cases where it has been responsible for data loss in RAID 0/1/10 modes.

In fact, I'd argue that it might be *more* reliable than a hardware RAID solution -- simply because hardware RAID devices 1. have less well tested drivers, and 2. provide for another piece of hardware which can catastrophically fail.

I have installed the two drives I want to mirror. I am using FreeBSD 4.4 and I can not seem to find were to setup raid 1 in the install process. Do I need to set up 2 slices on each drive and mirror the ad1a1,ad1b1 slices? When do I use vinum(8)?