New Hyper-V guest VM crashing.
Windows 2012 R2 Hyper-V host. It was running one VM for 2 years with no problems.
Added another VM and the new guest (PaperCut site server) starts to crash and eventually brings down the host. Pretty random. Can last a week or a day.
Performance shows plenty of hard drive space, RAM and no excessive CPU usage.
A reboot doesn't work. Only a forced shutdown.
Where is the best place start looking? Event Viewer.. Log files etc.
Any help would be greatly appreciated.
Added another VM and the new guest (PaperCut site server) starts to crash and eventually brings down the host. Pretty random. Can last a week or a day.
Performance shows plenty of hard drive space, RAM and no excessive CPU usage.
A reboot doesn't work. Only a forced shutdown.
Where is the best place start looking? Event Viewer.. Log files etc.
Any help would be greatly appreciated.
ASKER
Great point Alex.
32GB of RAM in the Host. Barley using 19%.
When I look in Hyper-V Manager > Settings for each guest.
Startup RAM: 1024MB
Min RAM: 512MB
Max RAM: 1048576.
If I try to change either Min or Max I get an 'Out of Bounds' error.
For example if I try to change Min RAM the error says
'Out of Bounds' select a number between 32 and 512
* Dynamic memory is enabled.
32GB of RAM in the Host. Barley using 19%.
When I look in Hyper-V Manager > Settings for each guest.
Startup RAM: 1024MB
Min RAM: 512MB
Max RAM: 1048576.
If I try to change either Min or Max I get an 'Out of Bounds' error.
For example if I try to change Min RAM the error says
'Out of Bounds' select a number between 32 and 512
* Dynamic memory is enabled.
You I'm curious about the maximum RAM, i'm pretty sure that's 128GB
I'd drop your maximum memory to 4096
I'd drop your maximum memory to 4096
Oh you'll need to shut the server down btw :-)
ASKER
Ah, so shut each VM to re-allocate RAM.
Will do at end of business today.
Many thanks, Alex.. will let you know.
Will do at end of business today.
Many thanks, Alex.. will let you know.
SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
ASKER
will do..
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
so you're going to throw 8GB of memory when it probably doesn't need it, at least do some perfmon with the server running stable before upping it to that.
SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
With 32GB of physical RAM there's not a lot there to play with.
What does the original VM do?
Dynamic Memory is great for low load VMs like domain controllers and file/print servers that have not SQL/WID database setups. For anything else, a fixed memory set is better.
Without knowing the original VM's workload I suggest:
8GB vRAM VM 0 (Original)
16GB vRAM VM 1 (PaperCut which probably needs more resources)
For vCPUs stick with the number of physical cores - 1 for vCPU count totals on the guests.
I have two very thorough EE articles on all things Hyper-V:
Some Hyper-V Hardware and Software Best Practices
Practical Hyper-V Performance Expectations
What does the original VM do?
Dynamic Memory is great for low load VMs like domain controllers and file/print servers that have not SQL/WID database setups. For anything else, a fixed memory set is better.
Without knowing the original VM's workload I suggest:
8GB vRAM VM 0 (Original)
16GB vRAM VM 1 (PaperCut which probably needs more resources)
For vCPUs stick with the number of physical cores - 1 for vCPU count totals on the guests.
I have two very thorough EE articles on all things Hyper-V:
Some Hyper-V Hardware and Software Best Practices
Practical Hyper-V Performance Expectations
@Alex Green
Yes, I would run 8GB of RAM initially and reduce as necessary. The reason for this is in a production environment, I would rather have too many resources dedicated to the box than not enough.
Yes, I would run 8GB of RAM initially and reduce as necessary. The reason for this is in a production environment, I would rather have too many resources dedicated to the box than not enough.
Less is more, unfortunately you're not quite understanding the intricacies of the hypervisor level, the second you start assigning 25% of the available memory to a single VM you end up throwing your memory management out of the window.
You cannot assign 8GB of memory to a single VM when the host only has 32gb.
You cannot assign 8GB of memory to a single VM when the host only has 32gb.
ASKER
Apologies for the late response but I had to see if it would indeed stay up.
Disabling dynamic memory has done the trick for well over a week - even though there was plenty for 2 VMs..??
Many thanks for all the suggestions
Disabling dynamic memory has done the trick for well over a week - even though there was plenty for 2 VMs..??
Many thanks for all the suggestions
Is it under more stress when you are running it and it falls over? How much memory in the host and how much have you assigned to the VM