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Virtualbox VM Slows down the host

PostPosted: 16. Jun 2021, 19:19
by Orsa
Few versions of Virtuabox ago everything was rather beautiful and work.
In few recent installations the host Windows becomes very very slow.

I am new to the forum and not sure what information would be useful to provide but I will try to get it if someone describes what info is needed to diagnoze.
Here is what is happening.

I have Windows 10 Professional Host with 16GB memory, 4CPU 128 MB video memory
Installed latest ubunut 20.4
Allocated 7GB, 1 CPU, 32 video memory to VM.
VM starts stops fine and overall works.

After some time though applications running on the host start striving or memory. Slack, Chrome, Outlook all freezes.

This started happening a few months ago with some new version of virtualbox by now it is hard to track which one.
I tried all the settings, lowering memory allocation to VM. Nothing helps.

I used to run windows 10 with 16GM memory and 9GM given to VM and 2 out 4 CPUs given to VM. Everything was OK.

Wondering if someone faced this issue.
Thank you for help.

Re: Virtualbox VM Slows down the host

PostPosted: 16. Jun 2021, 22:44
by scottgus1
Please right-click the guest in the main Virtualbox window's guest list, choose Show Log.

Search the far left tab's log for this text:

Attempting fall back to NEM

If you find it, Hyper-V is enabled. See HMR3Init: Attempting fall back to NEM (Hyper-V is active).

If you don't find that text, save the far left tab's log, zip the log file, and post the zip file, using the forum's Upload Attachment tab.

Re: Virtualbox VM Slows down the host

PostPosted: 16. Jun 2021, 23:26
by Orsa
Attached the log.

Nothing about NEM. I checked that Hyper-V is not installed on my Windows. I do not use it.

Thank you for your reply.

Re: Virtualbox VM Slows down the host

PostPosted: 17. Jun 2021, 10:19
by Martin
00:00:03.785651 Host RAM: 16186MB (15.8GB) total, 5401MB (5.2GB) available
00:00:03.947328 RamSize <integer> = 0x00000001ba100000 (7 416 578 048, 7 073 MB, 6.9 GB)

You don't have enough free ram for this guest, so the host probably is using swap slowing everything down.

Re: Virtualbox VM Slows down the host

PostPosted: 17. Jun 2021, 10:51
by mpack
Only two cores available as well - so the host slowing down is kinda inevitable, at least if the VM is working. If you want to run two 64bit OS on one PC then IMO you need a quad core at least.

I would reduce the VM RAM to 4GB, or free up more host RAM: something is hogging a humungous chunk of it.

Also increase graphics RAM to 128MB and enable 3D acceleration: running fullHD or better (2560x1335 !!) graphics without hardware acceleration (especially on one core) is another common cause of slowdown (32MB is less than 3 frames worth of buffering at the latter resolution).

Re: Virtualbox VM Slows down the host

PostPosted: 17. Jun 2021, 16:50
by Orsa
Thank you. Will give it a try.

Chrome usually eats a lot on the host system.