How to cure "black screen" in virtual machines on Hyper-V?

Question

Hyper-V

Good afternoon! Tell me, I have never contacted Hyper-V, but everything seems to be elementary simple, at first glance, but there are problems. It costs Windows Server 2012 R2, on it the only role is Hyper-V. There are only two Windows Server 2008 R2 virtual machines, one for a terminal server for 1C, the second for some employees, as well as a terminal. Host machine - an old server in excellent condition, Xeon E5520, 12Gb RAM. Everything works through one setevushka.

The problem is that after some time the virtual machine hangs with a black screen. Sometimes they drop in a minute, sometimes they don't. However, even to a hung virtual machine, you can get through RDP, but you can’t see anything other than blackness. At first I sinned on the dynamic allocation of RAM, but after the shutdown the problem remained. The servers are allocated 5120 MB of RAM each, which should be enough for a couple of desktops (namely, that's how much is used) and an office with a browser. I watched the logs, didn't notice anything special.

How to overcome this problem?

Answer 1

1. check the RAM for bitness.
2. processor time is busy in the trash with something (either the percent takes off the load and leaves the rest state
0_o for a long time) 3. the screw sags (possibly with a lot of virtual machines)
further tambourine in hand and dancing around.

Answer 2

Look at the task manager, well, in the end, the answer is most likely in the log viewer either on the host or inside virtual machines.

Answer 3

It is necessary to check the logs of the server and virtual machine OS, check the hardware, installed drivers (including those for guest OSes).

Answer 4

usually this happens when the host machine has problems, that is, at the moment when the black screen "sags" performance, from virtual machines this can be determined by the resource monitor, in the CPU graph there is a parameter% of the maximum, when there is a drawdown% drops heavily, this can be seen if monitor. Why there is a drawdown, you need to check already on the host machine, all of the above is possible

Answer 5

I looked at the logs, but I didn’t see anything sensible either on the host or in the virtual machine ... I played around with the processor settings, picked up the drivers. Let's see how it will work.
UPD the first day - the flight is normal.

Answer 6

perhaps the situation is similar to what I had: I got the
second virtual machine by copying the folder of the first one. thus got two identical folders with two virtual machines that successfully started at the same time. however, after working for an indefinite amount of time, one of them inevitably fell into a black screen. poking around in the settings, I found that both virtual machines refer to the use of one logical disk (in the source folder of virtual machine No. 1). how they could work in parallel with one disk is unclear .. but after correcting this misunderstanding, the black screen no longer appeared.