Restore virtual screen to dynamic size

[jnb]

Windows 11. Latest VB 7.0.14r161095. Linux Guest, with Guest Additions.

Because of a problem I was having with screen (separate issue, might raise a topic for that) I went into VB's View > Virtual Screen 1 and picked a Resize to ... fixed size. I had never done that before.

Depending on size, that now means either I get a guest desktop area smaller than the Windows window (with white borders to fill) or I get scrollbars to reach the desktop area beyond the size of the Windows window.

But previously, with Guest Additions, I had no such fixed size, if I resized the Windows window the guest desktop resized to fit whatever size I dragged to, no white borders or scrollbars. Now the View > Virtual Screen 1 always has the item I picked selected and I cannot unselect some fixed size. If it is relevant, I reinstalled Guest Additions but it made no difference. How do I get back to the original/default dynamic resizing behaviour without being locked to some fixed size, please?

EDIT
I posted this in Windows Hosts because I am looking at the View > Virtual Screen 1 menu item of VB as a Windows window. But I don't know, maybe it's an issue of the Guest Additions in Linux. If so, please excuse me and feel free to move this over to Linux Guests.

I don't know if the following is relevant. The manual states for Auto-Resizing that a process of `VBoxClient --display` should be running. There are several such processes running, including a `--vmsvga-session`, but none with `--display`. FWIW I tried manually setting off a `VBoxClient --display` and that worked and runs but made no difference. Of course, for all I know this might be required to run from the start.

[fth0]

The often ignored aspect (also described in the VirtualBox User Manual) is having the Linux kernel headers installed in the Linux guest OS, so that the VirtualBox Guest Additions can build their kernel modules and supersede the often ancient versions the Linux distribution brings with it.

[jnb]

Hi @fth0, thank you for replying.

I am afraid I don't understand: are you saying this is handled by Guest Additions, if they were working I would not be stuck with "fixed resolutions"? Then, as I said, I have always installed GA, and I have re-installed them to make sure (because I think I know Linux updates replace kernel modules, so then I need to re-install GA to re-overwrite them). And I see GA rebuilding kernel headers. But that has made no difference. It worked fine for years, now it does not.

I am suspecting
(a) This question thus belongs in Linux Guests not Windows Hosts? If so, feel free to move it there (if you are an admin), or should I create a new topic there myself?
(b) Does this imply my installed GA is not working right? Should I look in/post a log file?

[jnb]

Further update: went over to Linux Guests, my situation is all related to:

viewtopic.php?t=110982
viewtopic.php?t=110882
viewtopic.php?t=110962

I have appended a post at viewtopic.php?p=546809#p546809.

It was the screen flickering (and also square-block-cursor) which originally made me select a fixed resolution, which I am now stuck using, to be able to use VB/Ubuntu again. Looks like dealing with this is "a work in progress". If I understand right, GA is not working right with kernel/Wayland now, I think I have to do fixed resolution to deal with unusable flickering and that means I won't be able to do GA dynamic size. I'm still not sure whether my GA is really working (the 3rd topic above), but I think I should manage as I am for now and await a new VB/GA version?

[fth0]

Trying to answer your questions in order of appearance:

How do I get back to the original/default dynamic resizing behaviour without being locked to some fixed size, please?

AFAIK, you need the menu item View > Auto-resize Guest Display being checked and working Guest Additions (GA) in the guest.

I posted this in Windows Hosts because I am looking at the View > Virtual Screen 1 menu item of VB as a Windows window. But I don't know, maybe it's an issue of the Guest Additions in Linux.

Would probably have been better there, but I can simply ignore that. (I'm no moderator so I cannot move this thread.)

The manual states for Auto-Resizing that a process of `VBoxClient --display` should be running. There are several such processes running, including a `--vmsvga-session`, but none with `--display`.

I think this depends on the Linux distribution and the windowing system in the guest. My Linux Mint guest with X11 only uses VBoxClient --vmsvga, for example. If you're using Wayland in your Linux guest OS, switch to X11 for a test.

I am afraid I don't understand: are you saying this is handled by Guest Additions, if they were working I would not be stuck with "fixed resolutions"?

Yes, this and the checkmark mentioned above: Auto-resize Guest Display informs the GA when you change the VM window's resolution on the host side (via dragging at the VM window's corners/edges or via the VM window's menu like you did).

Then, as I said, I have always installed GA, and I have re-installed them to make sure (because I think I know Linux updates replace kernel modules, so then I need to re-install GA to re-overwrite them). And I see GA rebuilding kernel headers.

Ok, then it has probably worked, and you can ignore my somewhat snarky comment in my previous post. You can also check the version with sudo modinfo vboxguest inside the guest, and you'll notice if it didn't work.

I'm still not sure whether my GA is really working (the 3rd topic above), but I think I should manage as I am for now and await a new VB/GA version?

If X11 vs. Wayland is the background reason, you might have to wait for VirtualBox 7.1, which probably supports Wayland better than VirtualBox 7.0 (not saying that Wayland support will be complete then).

[jnb]

Hi @fth0,

Thank you for replying.

AFAIK, you need the menu item View > Auto-resize Guest Display being checked and working Guest Additions (GA) in the guest.

If I had seen any menu item/checkbox Auto-resize Guest Display you may be quite sure I would have pressed it The whole point of the question is that I have no such, just a list of fixed resolutions on radiobuttons where I have to pick one of them. Now, it might well be that when this used to work without any problem that option existed, but it does not now.

Let's be clear: I am looking at VB's menu View > Virtual Screen 1. If I am supposed to see the GA auto-size checkmark anywhere else, please let me know?

Otherwise this is why I don't understand the situation I seem to be in and am wondering if it is telling me that the GA at least for display are no longer working, despite re-installation?

OMG! Now I see it is an item at the View menu level!! I am so sorry, I have been looking in the Virtual Screen 1 sub-menu from there, where all the resolutions are shown. Personally I would have expected an option to not pick any of these to be where they are, not elsewhere! OK, clicking that finally reverts me to the dynamic sizing I have always had. I only got into this mess because I had to pick a fixed size in order to stop the "extreme screen flickering/corruption* problem I am sharing with others over in Linux Guests with others (viewtopic.php?p=546809#p546809), certainly under Ubuntu 22.04 + Wayland. So I will see how it goes now that i am back in dynamic sizing.

Thank you so much for your time, sorry it came down to my not spotting when a menu item lives!

[fth0]

You're welcome!

If you had read my previous post more closely, you'd noticed that I explicitly provided the menu path.