create softraid

RichardF

RichardF

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I was given a fujitsu rx100 s5 server. It's a 1u server, two sata disks. And probably not a real raid controller.
After installing CentOS mapper\ghjkljopoiuyt67890-poihgt678i wasn't found recognized whatever, so I read something here and there and realized maybe this is not a real raid card.

so I reconfigured the raid card not to use raid.

So now I am trying to create a softraid from within Centos.
mdadm is installed, but what is the best way to do this?

I added those lines to mdadm.conf
DEVICE /dev/sda1 /dev/sdb1
ARRAY /dev/md0 devices=/dev/sda1,/dev/sdb1

with this command
mdadm -C /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb2
I get this message:
mdadm: Cannot open /dev/sda1: Device or resource busy
mdadm: create aborted

with this command
mdadm --verboxe C /dev/md0 -level=1 --raid-devices=2 /devsda1 /dev/sdb2
I get this message
mdadm: An option must be given to set the mode before a second device is listed

What am I doing wrong?
 
This most likely isn't the best forum for a hardware question, which is what you're really asking.

First make sure that when you've turned off RAID your disks are really called /dev/sda1 and /dev/sdb1.

If so, then the problem is that you have to unmount the /dev/sda1 drive before you can set up the array.

You may be able to do this from a rescue mode, but you'll more likely need to run a live distribution (botted from a CD, DVD, or usb-drive, in order to set it up.

You can google for creating RAID on an already running box.

Jeff
 
tnx jeff

I have a bootable ubuntu usb stick. I don't know if the server can boot from usb, but I'll try to make a CD with CentOS, if possible.

In an other post you wrote that you used raidtools, but when i google raidtools I find old sites and topics. Is raidtools still alive?
 
RichardF said:
I have a bootable ubuntu usb stick. I don't know if the server can boot from usb, but I'll try to make a CD with CentOS, if possible.
Click to expand...
Not CentOS; if you can do it with CentOS then you can do it with a single-user login to your server, because CentOS isn't a live distribution.

I'd recommend either ubuntu or knoppix.
In an other post you wrote that you used raidtools, but when i google raidtools I find old sites and topics. Is raidtools still alive?
Click to expand...
I really don't know. Some of my servers have it; some don't.

Jeff
 
RichardF said:
tnx jeff
I didn't know that not every linux version can be booted from cd/usb
Click to expand...

He did not say that. He said "CentOS isn't a live distribution."

You can still boot from a CentOS usb. I do it all the time when doing remote OS installs. But it will probably not give you everything you need to do what you need to do.

A Live distro gives you a desktop environment with more functionality.
 
I fixed it.
centos softraid howto

I could follow it almost to the letter. The only difference was creating the raid on sda first and then use the clone option for sdb
Then I installed CentOS.. rebooted
No OS found :(
I was thinking.. I didn't make a raid config.. the setup saw the disks, I created the right partitions, during installation I saw both LED's burn simultanously, so mirror was active.
Then I went into the BIOS disabled the SATA-raid card totally saved changes
Rebooted and CentOS booted very well!
So for installing Centos on a Fujitsu Primergy RX100 s5, just disable the sataraid card and you're fine.
 
Last edited:
I thought you were trying to set up software on an existing system that did not currently have software raid.
 
well.. maybe that's because of my english. I can write it, but to express what I actually mean is a lot more difficult. And other part of the problem is my inexperience with Linux / jargon.

It was a fresh install. But still I learned something. tnx
 
On a fresh install its really easy except for the bios problem you had. I do it all the time.
 
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