Recently i had to reinstall my old (but still working) server. I have bought Smart Array P400 instead of my old Smart Array E200, added new harddrives (WD Caviar Black 1TB x 2). And there was an issue regarding that on CentOS 7.x (RHEL 7.x) there is no more drivers for that controller. This was bad for me.
I have started to google the internet and have found a solution for this:
Solution was simple:
- Download drivers from here http://elrepo.org/people/akemi/testing/el7/isos/
- Add above driver for CentOS 7 during boot process
- Install CentOS 7
This is the theory, in practice it look like this
- Download drivers from link provided above
- Burn it into USB stick via dd command
- Insert CD/DVD with CentOS 7.x and USB stick into USB port
- Boot from CD/DVD
- During boot proces hit ESCAPE key
- Enter command linux dd
- Now we will see screen like this
I have choose 
- Now we have question about choose driver – choose 
- Now we have loaded the driver
- We have loaded the driver and we can proceed with boot
- Now CentOS 7.x is booting
- After that i have proceeded with CentOS 7.x installation.
After steps above I was able to install CentOS 7.x on my old HP Proliant ML 110 G5 server with Smart Array P400.