1. failed to boot from USB for installation.
followed dd command in https://wiki.centos.org/HowTos/InstallFromUSBkey to create a bootable thumdrive without error, but the USB thumdrive is not detected in the BIOS. My motherboard is GA-P55A-UD3. So the easier way for me is to burn the ISO to a DVD disc.
[ Added Later on ] during BIOS upgrade from version F10 to F11 , I found out the USB thumdrive was not detected due to the extendible USB cable was plugged into USB3.0 port. When I changed to USB2.0 port, my thumdrive is back.
2. I have two hard disks : 2TB and 3TB. Attempted to install on the newly bought 3TB hard disk. Remembered hit kind of internal error. So I decided to install it on the 2TB hard disk.
3. This time round, I choose the software set GNOME-Desktop instead of default minimal installation, which gave me no network, no GUI. That was troublesome.
4. When I install the centos 7.1, the SATA control mode is ACHI. I had Ubuntu 15.04 and CentOS5.11 installed in this computer. The installation finally completed successfuly. And luckily, it didn't touch the GURB2 bootloader of my existing Ubuntu's.
5. However when I boot centos7.1, it panic at "no floppy controller found" and failed to show the GUI. I had no floppy driver and it is shown None in BIOS.
6. Luckily, when I change the SATA controller mode to IDE. The centos7.1 finally boots up. That's is the workaround for the time being. Ubuntu 15.04 will be still the main workstation.
[ Added Later on ] After BIOS upgrade from version F10 to F11, this issue is gone too. Worth it the upgrade. I can stay with ACHI finally.
By upgrading the BIOS, I also gained the stability of Memory, to let my 4x4GB pieces of memory to run at 1600Mhz, and overclocking the CPU from 2.8Ghz to higher frequency @ 3.2GHz. In Ubuntu, tools like hddtemp, sensors, psensor can tell the temperature inside.
cat /proc/cpuinfo helps to tell CPU speed.
This is article introduce rufus and helped to create a bootable MS-DOS in USB drive. In fact, I don't need it. It only after BIOS upgrade, I found there is Q-flash can do the upgrade without needing to boot into any OS.