I just recently got 2 320GB Seagate SATA Barracudas and put them in a hardware Raid 1 array on my Epox 9-HDAI Pro. The array shows that it is working and I KnoppMyth is successfully installed on it, but I'm not sure if everything is mirroring correctly. When I ran iostat on both drives I only get anything on the first one. It looks like:


Is it just reading it weird because the HW is mirroring the data and not the OS?

You should only see one disk. RAID-1 will present 1 drive to the OS (also referred to as virtual, logical, etc.). See http://www.acnc.com/raid.html for more information.

Damn, that's what I thought. Is there a way to do this now that I have everything installed without messing everything up. I do not want to reinstall and I am open to a software solution.

You probably have what is known as a "fake raid" controller. In my experience linux tends to ignore them as linux software raid is generally better.

Argg... this is unfortunate. I just spent a while getting 30GB of files to transfer over and my drivers installed. Can I setup software raid with just 2 drives or should I have another to install the OS on. I'm not really in the mood for taking it all back apart and putting in another drive.

Huh? You said you "put them in a hardware Raid 1 array", what are you trying to accomplish? Configuring 2 drives in RAID-1 will present a single drive to any OS, what you are seeing is expected.

So, what exactly are you trying to do?

I'm saying since the hardware solution did not work, but knoppmyth is already installed on one drive and working, is there a way to clone the current HD that is working to the one that is empty and get raid 1 working in software inside the OS without reinstalling knoppmyth and erasing everything.

What makes you think it's not working? From reading this thread, it looks like it IS working, but you're just not being very appreciative!

I'm not sure I understand. In the second post, slowtolearn said that raid 1 should only appear as 1 disk where as for me it's appearing as two seperate ones of which only one is showing any I/O activity. I was under the impression that it was not working in its current state.

Sorry if my post sounded like that, it's not what I intended. You stated you configured 2 drives into a RAID-1. You should only see 1 drive, as there is only 1 drive presented to the OS.

No, you are misinterpreting the output. You physically have only 1 drive, which is the synced pair of 320Gb drives. You don't have a /dev/sdb. It's the hardware's job to keep the two in sync...

Now, if it were a RAID-0 configuration, that would be a different story. I would suggest perusing the link I posted earlier, as well as this one http://www.storagereview.com/guide2000/ref/hdd/perf/raid/index.html which gives a fairly good overview of RAID while not getting too deep.

But I see two. If I go in to cfdisk I can see that /dev/sdb is empty and /dev/sda is the only one operating.

Really? Then it would appear that the hardware RAID is misconfigured. If you run what is returned?

Unfortunately I don't know any tricks to save the existing data when configuring an array - Most RAID utilities will wipe the drives upon initilization of the array (or at least they used to, not sure about the more current ones. You should check with your RAID controller's manufacturer for options).

I get:

That certainly doesn't look right, with the double entries for each disk (SATA huh? Sorry, missed that part in the first post). As mad_paddler mentioned you may have a pseudo-hardware controller on that motherboard, you should check with the manufacturer to be sure it's properly supported in Linux. Does it match anything on the list found here http://linux-ata.org/faq-sata-raid.html ? Keep in mind this may not be completely up-to-date.

Exactly, I'm just really confused on how to setup a RAID array where everything is mirrored. So far it seems as if hardware RAID is required, or I need a non-raid drive to install software RAID to. Any solutions?