Needed entropy for ssh?

[Bestbeast]

Hello guys,

I have just had a problem while trying to login into my debian 10 VM, and it seems that ssh service takes a lot of time to startup, and some times timing out. I just searched a bit, and people was saying because of lack of entropy in VMs, and recommended installing haveged. As soon as I did, the problem was solved.

Can someone explain me why is this happening, and why should I install haveged to make it work? Am I missing something in my VM config?

Kind regards

 

[Bestbeast]

Hello,

It seems debian 10 comes with rng-tools and it fails when it boots, any idea on why?

Kind regards

 

[mbosma]

Debian 10 is stricter in accepting random data to fill /dev/urandom, this is why everything takes longer to start when running in a vm.
Here's a page from Debian about this "issue":
https://wiki.debian.org/BoottimeEntropyStarvation

To fix this issue install havaged like the article states, or on proxmox you can add a virtio device by adding the following rule to your vm's config:

args: -device virtio-rng-pci

 

[janssensm]

From this wiki and post from Daniel Lange I understand that haveged should be used as last resort.
So adding virtio-rng-pci should be the way to go?
If so, if this a structural issue, perhaps this should be a selectable item in proxmox instead of argument.

 

[Bestbeast]

From this wiki and post from Daniel Lange I understand that haveged should be used as last resort.
So adding virtio-rng-pci should be the way to go?
If so, if this a structural issue, perhaps this should be a selectable item in proxmox instead of argument.

Yes, strongly think so

 

[mbosma]

I use this solution myself too.
Having one daemon to provide isn't that bad, when running 100+ vm's on a host however feels like a waste of resources.