Centos – Increasing Command Line Resolution Centos 6.4 VirtualBox

centosvirtualbox

I running CentOS 6.4 in just CLI mode. However, I have a 1080 monitor and the resolution from the CLI interface is horrible. Do I still have to install Guest Additions in order to increase display resolution.

Best Answer

2.6.X kernels

You can increase the resolution at the console like so via your /etc/grub.conf file. Find the kernel ... line pertaining to your system booting up:

kernel /vmlinuz-2.6.32-358.11.1.el6.x86_64 ro 
        root=/dev/mapper/vg_mungr-lv_root rd_LVM_LV=vg_mungr/lv_root 
        rd_LVM_LV=vg_mungr/lv_swap rd_NO_LUKS rd_NO_MD 
        rd_NO_DM LANG=en_US.UTF-8 
        SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us 
        console=ttyS0,115200 crashkernel=auto vga=791

Where some of the values you can use for vga=:

791 - 1024x768, 16 bit
792 - 1024x768, 24 bit
794 - 1280x1024, 16 bit
795 - 1280x1024, 24 bit

Newer kernels (3.x)

As you move forward to newer versions of the Linux kernel that make use of KMS you'll need to change from using vga=, so you'll need to pay particular attention to what version of the kernel you're using. You can read more about it in this U&L Q&A titled: How to set the resolution in text consoles (troubleshoot when any vga=… fails).

References

How to change console resolution on Linux ( RHEL / CentOS / Fedora / etc)

Related Solutions

CentOS – How to Install Virtualbox Guest Additions via Command Line

... finally this worked for me, should also work for anybody else trying to install VirtualBox Guest Additions on a CentOS (x86_64) virtual server in command line mode.

# yum update
# yum install dkms gcc make kernel-devel bzip2 binutils patch libgomp glibc-headers glibc-devel kernel-headers elfutils-libelf-devel
# mkdir -p /media/cdrom
# mount /dev/scd0 /media/cdrom
# sh /media/cdrom/VBoxLinuxAdditions.run

Note: In CentOS 7 and higher the cdrom is at /dev/sr0 instead of /dev/scd0.

When the process is complete, reboot the system. That's all.

VirtualBox Display – Increasing Screen Size/Resolution on a VirtualBox Instance of CentOS

A maximum resolution of 800x600 suggests that your X server inside the virtual machine is using the SVGA driver. SVGA is the highest resolution for which there is standard support; beyond that, you need a driver.

VirtualBox emulates a graphics adapter that is specific to VirtualBox, it does not emulate a previously existing hardware component like most other subsystems. The guest additions include a driver for that adapter. Insert the guest additions CD from the VirtualBox device menu, then run the installation program. Log out, restart the X server (send Ctrl+Alt+Backspace from the VirtualBox menu), and you should have a screen resolution that matches your VirtualBox window. If you find that you still need manual tweaking of your xorg.conf, the manual has some pointers.

There's a limit to how high you can get, due to the amount of memory you've allocated to the graphics adapter in the VirtualBox configuration. 8MB will give you up to 1600x1200 in 32 colors. Going beyond that is mostly useful if you use 3D.