VB show resulution up to 1024

[Alexey Kuznetsov]

Windows guest do show resultion up to 1024. Also after reboot resolution still stay bad. Also in games you can't set resolution to max 1440x900.

[Michael Thayer]

Have you looked at section 9.12 in the user manual ("Configuring the maximum resolution of guests when using the graphical frontend")? That may be the reason for what you are seeing.

[Alexey Kuznetsov]

thx for note, but:

- "they will not be allowed to use screen
resolutions greater than the host’s screen size", which wrong, my host resolution, as you can see, 1440x900, but windows allow maximum 1024


-[axet@axet-laptop ~]$ VBoxManage getextradata global GUI/MaxGuestResolution
VirtualBox Command Line Management Interface Version 2.1.2
(C) 2005-2009 Sun Microsystems, Inc.
All rights reserved.

Value: auto
[axet@axet-laptop ~]$ 

[Frank Mehnert]

Axet, this is a typical problem. The Windows guest has a some predefined resolutions, for example, 1024x768, 1152x864, 1280x960, 1280x1024, 1400x1050, 1600x1200, 1920x1440. In setting auto, the VMM will check resolution if this resolution fits into the current host screen resolution. Fitting means that the VM window (including window decorations) does completely fit into the current desktop (this is the screen resolution minus the menu bar and the task bar). This mechanism is meant to restrict the default video resolution of the guest to the visible space, otherwise a VM guest would probably start with 1920x1440 the first time.

If you don't like this mechanism you can override it manually as described in the manual.

[Alexey Kuznetsov]

Thanks Frank! But then here is a bug, because i start machine in maximized window state and still got 1024x768 resolution. When i do restore/maximize on window, Windows guest resize it self to right window size!

[Frank Mehnert]

You mean you start the VM with a maximized window state or in fullscreen (I ask to be sure)?

As soon as the guest additions are active, the guest will resize to any resolution which was forced by the host. So if the user resizes the VM window, the guest will be set to exactly this resolution without that check I mentioned before. Of course there is an additional check if the guest video RAM is sufficient. So if the window is maximized or if the VM is set to fullscreen, then the guest will receive this resize event and it will handle it properly as soon as the guest additions get active. At least this is this how it is designed to work...

[Frank Mehnert]

Hmm, actually I remember that we changed this mechanism a little bit. The video mode hint which is sent from the host to the guest to tell the guest to change the video mode is not sent as long as the guest additions are not active. Therefore any resize event is ignored until the guest additions are active. On the other hand, the guest additions will restore the last video mode which was active when the guest additions finished last time. So if you left your guest in the maximized window state, this window size will be restored the next time the guest comes up and the additions get active.

[Alexey Kuznetsov]

I told about VM with a maximized window state...

I tried to restore/maximize VB window and reboot windows guest with guest additionals installed. You right, i got right resolution.

Probably guest additionals should additional check resolution after os fullloaded, whihch can prevent low resolution mode from last boot.

[Frank Mehnert]

Please reopen if this is still relevant with VBox 3.1.6.