xrandr 명령이 작동하지 않는 이유는 무엇입니까?

내가 뭘 잘못하고 있는지 알고 싶습니다. 비디오 카드는 모니터와 해상도를 자체적으로 전환하는 것 같아서 이러한 옵션을 제거하고 내가 사용하는 옵션만 유지하고 싶습니다. 보시다시피 작동하지 않았습니다.

rt@mach:~$ xrandr --rmmode HDMI1 1280x1024
usage: xrandr [options]
  where options are:
  -display <display> or -d <display>
  -help
  -o <normal,inverted,left,right,0,1,2,3>
            or --orientation <normal,inverted,left,right,0,1,2,3>
  -q        or --query
  -s <size>/<width>x<height> or --size <size>/<width>x<height>
  -r <rate> or --rate <rate> or --refresh <rate>
  -v        or --version
  -x        (reflect in x)
  -y        (reflect in y)
  --screen <screen>
  --verbose
  --current
  --dryrun
  --nograb
  --prop or --properties
  --fb <width>x<height>
  --fbmm <width>x<height>
  --dpi <dpi>/<output>
  --output <output>
  --auto
  --mode <mode>
  --preferred
  --pos <x>x<y>
  --rate <rate> or --refresh <rate>
  --reflect normal,x,y,xy
  --rotate normal,inverted,left,right
  --left-of <output>
  --right-of <output>
  --above <output>
  --below <output>
  --same-as <output>
  --set <property> <value>
  --scale <x>x<y>
  --transform <a>,<b>,<c>,<d>,<e>,<f>,<g>,<h>,<i>
  --off
  --crtc <crtc>
  --panning <w>x<h>[+<x>+<y>[/<track:w>x<h>+<x>+<y>[/<border:l>/<t>/<r>/<b>]]]
  --gamma <r>:<g>:<b>
  --primary
  --noprimary
  --newmode <name> <clock MHz>
        <hdisp> <hsync-start> <hsync-end> <htotal>
        <vdisp> <vsync-start> <vsync-end> <vtotal>
        [+HSync] [-HSync] [+VSync] [-VSync]
  --rmmode <name>
  --addmode <output> <name>
  --delmode <output> <name>

.

rt@mach:~$ xrandr --delmode HDMI1 1280x1024
X Error of failed request:  BadAccess (attempt to access private resource denied)
  Major opcode of failed request:  150 (RANDR)
  Minor opcode of failed request:  19 (RRDeleteOutputMode)
  Serial number of failed request:  29
  Current serial number in output stream:  30

.

root@mach:/home/rt# xrandr --delmode HDMI1 1280x1024
X Error of failed request:  BadAccess (attempt to access private resource denied)
  Major opcode of failed request:  150 (RANDR)
  Minor opcode of failed request:  19 (RRDeleteOutputMode)
  Serial number of failed request:  29
  Current serial number in output stream:  30

.

root@mach:/home/rt# xrandr --rmmode HDMI1 1280x1024
usage: xrandr [options]
  where options are:
  -display <display> or -d <display>
  -help
  -o <normal,inverted,left,right,0,1,2,3>
            or --orientation <normal,inverted,left,right,0,1,2,3>
  -q        or --query
  -s <size>/<width>x<height> or --size <size>/<width>x<height>
  -r <rate> or --rate <rate> or --refresh <rate>
  -v        or --version
  -x        (reflect in x)
  -y        (reflect in y)
  --screen <screen>
  --verbose
  --current
  --dryrun
  --nograb
  --prop or --properties
  --fb <width>x<height>
  --fbmm <width>x<height>
  --dpi <dpi>/<output>
  --output <output>
  --auto
  --mode <mode>
  --preferred
  --pos <x>x<y>
  --rate <rate> or --refresh <rate>
  --reflect normal,x,y,xy
  --rotate normal,inverted,left,right
  --left-of <output>
  --right-of <output>
  --above <output>
  --below <output>
  --same-as <output>
  --set <property> <value>
  --scale <x>x<y>
  --transform <a>,<b>,<c>,<d>,<e>,<f>,<g>,<h>,<i>
  --off
  --crtc <crtc>
  --panning <w>x<h>[+<x>+<y>[/<track:w>x<h>+<x>+<y>[/<border:l>/<t>/<r>/<b>]]]
  --gamma <r>:<g>:<b>
  --primary
  --noprimary
  --newmode <name> <clock MHz>
        <hdisp> <hsync-start> <hsync-end> <htotal>
        <vdisp> <vsync-start> <vsync-end> <vtotal>
        [+HSync] [-HSync] [+VSync] [-VSync]
  --rmmode <name>
  --addmode <output> <name>
  --delmode <output> <name>