When increase resolution in VM full screen not shown

[matmatt]

I'm using Virtual Box 5.1.22 on Mac OSX 10.12.5, and am running a VM containing Mint 18.2.

When I am in full screen mode and increase the resolution of the VM to 2560x1600 (the resolution of the screen), only part of the screen is shown.

I've installed Guest Addition, but no joy.

Any tips would be massively appreciated...

[mpack]

I've installed Guest Addition, but no joy.

Well, I don't know what you tried before that, because "full screen" is a feature of the Guest Additions. Maximizing the VM window will not give you full screen mode, you'll always have a windows frame and caption.

Install the Guest Additions, and be specific about what if anything doesn't work.

[matmatt]

Well, I don't know what you tried before that, because "full screen" is a feature of the Guest Additions. Maximizing the VM window will not give you full screen mode, you'll always have a windows frame and caption.

Install the Guest Additions,

As I said, I have installed Guest Additions. And I don't know what you mean by 'what you tried before that'... I spun up the VM and installed Guest Additions.

and be specific about what if anything doesn't work.

I'm also not sure how to describe this more specifically than 'only part of the screen is shown. I mean that I can see the top left of the screen, but not the whole screen. When it is at a lower resolution I see the full screen of the VM (ie. the task bar for example). When I increase the resolution the icons' physical size is unchanged, but I only see part of the screen, as though the full screen is being zoomed in on. I do have 'Auto resize guest display' enabled.

If there's more information I can provide that might be of use don't hesitate to let me know.

[mpack]

You said "I tried installing the Guest Additions but no dice", which to me implied that you thought there was something else you could have tried, so perhaps you didn't realize that fullscreen mode is a GAs feature. People occasionally confuse full screen with maximizing the window, that was the point where clarification was required.

I'm also not sure how to describe this more specifically than 'only part of the screen is shown.

Well, a screenshot might be worth considering.

In the VirtualBox manager, what is File|Preferences|Display|Maximum Guest Screen Size set to?

[matmatt]

You said "I tried installing the Guest Additions but no dice", which to me implied that you thought there was something else you could have tried, so perhaps you didn't realize that fullscreen mode is a GAs feature. People occasionally confuse full screen with maximizing the window, that was the point where clarification was required.

Ah, gotcha. No, I just meant to clarify that Guest Additions is installed as that's usually the first piece of advice people give.

In the VirtualBox manager, what is File|Preferences|Display|Maximum Guest Screen Size set to?

''Automatic'

The screenshot tool just gives a blank image, and I don't want to spend time fixing that until I'm convinced that I can use VirtualBox, so I've taken a lo-tec approach and attach a photo of the screen.

[mpack]

Please provide a VM log file. With the VM fully shut down, right click it in GUI. Select "Show Log" and save "VBox.log" (ONLY) to a zip file. Attach the zip here.

[matmatt]

Please find Vbox.log attached.

[mpack]

I'm not seeing much wrong.

Please clarify one thing for me. When in full screen mode, then by definition the display size is what it is (the full screen). Why are you then trying to change it?

I am seeing the switch to 2560x1600 in the log, so I'd say it should be working - unless there's a problem in the guest OS with rendering the guest desktop.

00:01:01.607100 VBVA: InfoScreen: [0] @0,0 2560x1600, line 0x2800, BPP 32, flags 0x1
00:01:01.607128 Display::handleDisplayResize: uScreenId=0 pvVRAM=0000000117595000 w=2560 h=1600 bpp=32 cbLine=0x2800 flags=0x1
00:01:01.607495 GUI: UIFrameBufferPrivate::NotifyChange: Screen=0, Origin=0x0, Size=2560x1600, Sending to async-handler
00:01:01.637828 GUI: UIMachineView::sltHandleNotifyChange: Screen=0, Size=2560x1600
00:01:01.637858 GUI: UIFrameBufferPrivate::handleNotifyChange: Size=2560x1600
00:01:01.637880 GUI: UIFrameBufferPrivate::performResize: Size=2560x1600, Directly using source bitmap content
00:01:01.684860 GUI: UIMachineView::storeGuestSizeHint: Storing guest-screen size-hint for screen 0 as 2560x1600
00:01:01.857850 GUI: UIMediumEnumerator: Medium-enumeration finished!
00:01:05.382100 VBVA: InfoScreen: [0] @0,0 2560x1600, line 0x2800, BPP 0, flags 0x5
00:01:05.382200 Display::handleDisplayResize: uScreenId=0 pvVRAM=0000000117595000 w=2560 h=1600 bpp=0 cbLine=0x2800 flags=0x5
00:01:05.382295 GUI: UIFrameBufferPrivate::NotifyChange: Screen=0, Origin=0x0, Size=2560x1600, Sending to async-handler
00:01:05.382516 GUI: UIMachineView::sltHandleNotifyChange: Screen=0, Size=2560x1600
00:01:05.382539 GUI: UIFrameBufferPrivate::handleNotifyChange: Size=2560x1600
00:01:05.382565 GUI: UIFrameBufferPrivate::performResize: Size=2560x1600, Using fallback buffer since no source bitmap is provided
00:01:05.386843 VBVA: InfoScreen: [0] @0,0 1232x734, line 0x1340, BPP 0, flags 0x5
00:01:05.386888 Display::handleDisplayResize: uScreenId=0 pvVRAM=0000000117595000 w=1232 h=734 bpp=0 cbLine=0x1340 flags=0x5

Do you have any Video Size hints set? If so then I would try removing them.

[matmatt]

Please clarify one thing for me. When in full screen mode, then by definition the display size is what it is (the full screen). Why are you then trying to change it?

Indeed, I would like the display size to be the full screen and I would like to see the entirety of the guest OS desktop at full resolution. As it is, the resolution is apparently being set, but it's as if the screen is being zoomed in upon so I can't see the full desktop. Note that in the photo I added earlier that the task bar cannot be seen.

unless there's a problem in the guest OS with rendering the guest desktop

Yes, it's as if there's a zoom in play.

Do you have any Video Size hints set? If so then I would try removing them.

I have none set.