Hyper-V memory config issues

[XcOM9876 9]

For a while now I've seen some performance issues where the server will become unresponsive and after a while it will return to normal, I think I am getting to bottom of it, making this more as an FYI for people in case they come across performance issues themselves.

I found that when I had dynamic memory enabled Emby would run fine up to a point when it would start to lag, I would see the memory allocated to the server increase but I wonder if it wasn't increasing fast enough even though I set a 25% buffer, or if Emby just doesn't like dynamic RAM, so I set a static amount of 4GB for Ubuntu Server 20.04.3 and Emby server and performance has increased no end, I still have odd issues now and again which require a reboot of the server, I think these are linked to the underlying server rather than Emby itself, next diags are to add more CPU cores and move the server storage to an SSD but I can't do this until my new hardware is delivered.

[Luke 42078]

Quote

Emby just doesn't like dynamic RAM

Hi, I haven't heard of this before, but I suppose it's possible.

[XcOM9876 9]

I am not sure if it's just something unique to my setup with me running server 2019 as a host and running Emby as a HyperV VM under Ubuntu, when I was gathering info I would see memory allocation increase to about 3.6GB but internally under the host it would begin to max out and no more would be allocated, the strange thing is the issues requiring a reboot but what I find strange is that none of my other VM's which also run the same version of Ubuntu don't exhibit the same issues, one of which is more IO, CPU, and RAM intensive.

If I ever get to the bottom of it I'll be sure to update you, especially if any of it is linked to how Emby interacts with the host/guest, but I can't see many people using my setup. 

Edited November 30, 2021 by XcOM9876

[Luke 42078]

You might find some helpful info here: 

 

[XcOM9876 9]

Cheers for that, I didn't find that page but I did find another technet article with similar issues which is what made me lock the memory allocation to 4GB, I would allocate more but I don't have enough spare at the moment lol, once my new hardware has arrived it will be going from 4 cores 4gb to 6 cores 8gb and spinning rust to SSD

[Carlo 4561]

Hi, I'm a huge fan of virtualization and containers and practically have my own cloud service.
But I have to ask, why are you running a VM hosting Linux to run Emby Server when it could have been installed on the host?  Everything would run better that way generally speaking.

Is this a temp thing to host a Linux server build until you get the machine ready?
What CPU do you have and how much memory do you have in the Windows Server?  Others VMs running or just this one?
How are you doing storage?  Is that pass through or virtual as well?
Which version of Ubuntu Server are you running?  It's headless correct?

[XcOM9876 9]

Hey,

so my setup is Server 2019 with Hyper V enabled, this hosts about 7 virtual machines which are all Linux based, there is Emby, Sonarr, Radarr, Home Assistant, a few other things, and a virtual load balancer to do L7 transporting so I only have 1 port exposed on my firewall and the load balancer routes the traffic based on rules.

The reason why I do this is because if the underlying hardware dies or OS dies then I don't loose the guest, I can just reload it on new hardware, or restore from a backup/snapshot depending on what is needed, I've tried Docker, and other container systems but honestly HyperV with full OS' is the best option for me.

The guest storage is all located on the host for the OS drives and hosts VHDx files for the HDD's, any shared storage needed to be located on the system are shared from the host via SMB, the media is located elsewhere but also shared via SMB and everything is mounted via the FSTAB file.

Host:

• Intel Xeon E5-2640V3
• 32GB ECC Registered DDR4 2400
• 240GB SSD for host OS
• 3TB HDD for guest OS drive storage
• 3TB HDD for guest supplementary storage
• Emby media is 36TB of spinning rust located on another server which is shared via SMB

Guests are a mix, but they are mostly Ubuntu Server 20.04 LTS or CentOS 8 with the exception of the load balancer and Home Assistant which are their own things, most have 2 cores and 2gb base ram which is dynamic, the only ones fixed is the load balancer and Emby, Emby also has 4 cores assigned to it but no hardware passthrough for hardware transcoding but all my media is in HEVC already and if it's not I have a VM running which searches and transcodes using a GPU if it finds something that's not HEVC.

Honestly it's what I am used to as I manage virtual environments in VMware and HyperV for a living and it has massive advantages over containers but the drawback is the overhead in performance requirements.

Edited December 4, 2021 by XcOM9876