Boot CentOS without a Video Card

Advance in this post I’m seriously considering the Mini-ITX technology in tandem with Sandy Bridge CPU for servers in the Datacenter: this to replace older equipment with server
by the consumption much lower.

With this in mind I bought the first kit “to test” just to see the feasibility of the project: in the shopping list was the cabinet 1U capable of hosting two motherboards, two
motherboards Mini-ITX, RAM , disks, and, of course, the two CPUs.

I admit my ignorance in terms of the Sandy Bridge CPU, so I did a no shopping careful looking exclusively to the economic factor at the expense of performance. The first mistake
was to choose a class CPU i5 not i7: Even if the clock and the number of cores is the same, i5 CPUs do not have HyperThreading for virtualized environments in which you only
have a 4 virtual CPUs instead of 8. It ‘s true, using the HT performance in virtualized environments are the result of several ambiguities, but not letting us in and letting us
off, I prefer the latter.

The second error concerns the CPU model: I5-3350P I bought that, compared to the I5-3350 (without P) is cheaper than some euro … and also has a “P” in the most: at first
glance a bargain! In fact I found out after the purchase that the CPU marked with the letter “P” are those for which the graphics section has not passed quality tests, so it is
disabled by Intel … therefore, the graphic cards Mini-ITX is not working because the CPU does not have the graphics section and it is necessary to purchase an external video

To me it does not matter: once installed the OS, the video section I no longer need because I will connect to the server via ssh always and only. So I provide to “loot” card
from another PC and install Linux.

Since I plan to use CLVM and do not have much time to spare, I put aside my trusty Debian and proceed to install CentOS 6.3. The installation proceeds smoothly and, once
configured the IP and rebooted the server a few times to be sure, turn off and remove the video card … and behold, the server will not start again!

To understand what happens I try to remove the hard disk and start the server (without video card) with the Arch Linux boot CD: I can get the IP address from my DHCP server
released, I start “blind” the demon SSH and see that everything runs smoothly from here: in short, is that CentOS want a video card to go!

After a few hours of testing, I was able to understand that the “culprit” is grub, so I changed the configuration to make sure that will start to using the serial output.

serial --unit=0 --speed=9600 --parity=no --stop=1
terminal --timeout=2 serial