Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

I tried to change the resolution using the following commands (found here):

Use xrandr to check the current configuration and available modes:

$ xrandr
Screen 0: minimum 64 x 64, current 800 x 600, maximum 32000 x 32000
VBOX1 connected 800x600+0+0 0mm x 0mm
   800x600        60.0*+
   640x480        59.9  

Use cvt to get the proper modeline for 1280x800:

$ cvt 1280 800
# 1280x800 59.81 Hz (CVT 1.02MA) hsync: 49.70 kHz; pclk: 83.50 MHz
Modeline "1280x800_60.00"   83.50  1280 1352 1480 1680  800 803 809 831 -hsync +vsync

Create the new mode using xrandr --newmode:

$ xrandr --newmode "1280x800_60.00"   83.50  1280 1352 1480 1680  800 803 809 831 -hsync +vsync

Use xrandr again to check that the mode was created successfully:

$ xrandr
Screen 0: minimum 64 x 64, current 800 x 600, maximum 32000 x 32000
VBOX1 connected 800x600+0+0 0mm x 0mm
   800x600        60.0*+
   640x480        59.9  
  1280x800_60.00 (0x11a)   83.0MHz
        h: width  1280 start 1352 end 1480 total 1680 skew    0 clock   49.4KHz
        v: height  800 start  803 end  809 total  831           clock   59.5Hz

However, when I try to add the new mode to the display with xrandr --addmode I get the following error:

$ xrandr --addmode VBOX1 1280x800_60.00
X Error of failed request:  BadMatch (invalid parameter attributes)
  Major opcode of failed request:  150 (RANDR)
  Minor opcode of failed request:  18 (RRAddOutputMode)
  Serial number of failed request:  18
  Current serial number in output stream:  19

Of course, if I try to set the new resolution for my current display it fails (the mode isn't associated to te display):

$ xrandr --output VBOX1 --mode 1280x800_60.00
xrandr: cannot find mode 1280x800_60.00
share|improve this question

2 Answers 2

up vote 3 down vote accepted

Seems that you're trying within VirtualBox. If it's the case, just install VirtualBox Guest Addition, you can get any resolution (by resizing the VirtualBox window)

share|improve this answer
    
Thanks, I had installed the Gust Additions but Ubuntu still only showed me 800x600 and 640x480. I thought that Ubuntu would show me bigger resolutions options and resize the vbox window according to the resolution selected.... and not the other way arround: resizing the vbox window would allow me to select bigger resolutions. –  Toto Oct 11 '10 at 13:57

you can use:

sudo xrandr --output VBOX1 --scale 1.5x1.5

you can change the 1.5x1.5 per another scale factor

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.