Nat stops responding after video

[filippos]

My host is CentOS7 and guest Ubuntu 16.04.3 (Linux 4.15.0-72-generic on x86_64)
I connected thru a NAT Network to apache2 https
When I transfer a big file the system stops responding until the whole file is transferred.
When I restart NAT everything is fine until a big file like a video is transferred again

Host CPU: Intel(R) Xeon(R) CPU E5-2620 0 @ 2.00GHz, 24 cores /
100% to Guest
Host RAM: 32GB /
30GB to Guest
VBOX: 6.0.14r133895

[socratis]

We need to see a complete VBox.log, from a complete VM run, where the problem occurs:

• Start the VM from cold-boot (not from a paused or saved state) / Observe or recreate the problem / Shutdown the VM (force close it if you have to).
• With the VM completely shut down (not paused or saved), right-click on the VM in the VirtualBox Manager and select "Show Log".
• Save only the first "VBox.log", ZIP it and attach it to your response. See the "Upload attachment" tab below the reply form.

[filippos]

Hi Socratis,

Here it is

From VM ping google.com
From Firefox https://IP_CENTOS:10000 (webmin) and ping stops asap.

On Centos, selinux is down

net tab

NetTab.png (72.3 KiB) Viewed 1120 times

Network tab

NatNet.png (74.87 KiB) Viewed 1120 times

[fth0]

For a test, give the VM only 8 vCPUs and 8/16 GB RAM and check if the problem persists.

[filippos]

I've already done tests with
CPU: 8 / RAM: 30
CPU: 4 / RAM: 24
The problem persists

It seems that NAT Network has problems with concurrent use

[socratis]

First of all, before I forget... Did you really obfuscate a private IP address? And a fake MAC address? Why, oh why? Security is a GoodThing™. Paranoia is not.

I connected thru a NAT Network to apache2 https

Can you explain that? Who connects to what? Where is the Apache server?

From VM ping google.com. From Firefox https://IP_CENTOS:10000 (webmin) and ping stops asap.

I'm sorry, but what does that mean?

Moving on to the VBox.log...

00:00:01.272081 File system of '/root/VirtualBox VMs/Ubuntu/Snapshots/{5bec9d72-1142-4758-9b60-56e30bf49147}.vdi' is ext4

Are you running VirtualBox as 'root'? Why do you do that? It strongly discouraged, from a security point of view.

00:00:00.075825 Host RAM: 32136MB (31.3GB) total, 31648MB (30.9GB) available
00:00:01.310042 RamSize    <integer> = 0x0000000780000000 (32 212 254 720, 30 720 MB, 30.0 GB)
00:00:01.310687 VRamSize   <integer> = 0x0000000001000000 (16 777 216, 16 MB)

You are assigning so much RAM to your Guest that you're really stressing your Host. Reduce the amount of RAM assigned to the Guest to 16 GB. On the other hand, the amount of VRAM that you have assigned is too low for today's graphical based OSes. Increase that to 128 MB of VRAM.

00:00:01.310034 NumCPUs   <integer> = 0x0000000000000018 (24)
00:00:02.040194 CPUM: Physical host cores: 12
00:00:02.040839 Full Name: "Intel(R) Xeon(R) CPU E5-2620 0 @ 2.00GHz"

You have assigned more CPUs to the VM than you actually have. The host is going to run low on resources, since VirtualBox cares about physical processors, not logical ones.

It seems that NAT Network has problems with concurrent use

How do you know that it's the NATnetwork and not the I/O?

You got to give us all the details and not try to obfuscate them. Read my signature just below...

[filippos]

Thanks,
Merry Christmas to all