Risks of using a jessie-backports kernel?

[ispirto]

I wonder if there are any stability or compatibility issues using jessie-backports kernel on latest Proxmox.

I'm particularly interested in using 4.9.0-0.bpo.1-rt-amd64.

 

[t.lamprecht]

4.9.0-0.bpo.1-rt-amd64.

This is a Kernel patched with the PREEMPT_RT realtime patch set [1] for realtime [2] support.
In can be wrong as I do not know your use case, but normally this is not needed or wanted on server hardware for virtualization.

Some disadvantages I can think of at the moment would be:
* it's not explicitly tested on Proxmox VE
* realtime patched kernel have also not much exposure to Hypervisor systems running KVM + LXC machines, AFAIK
* If you use ZFS you need to install the module with DKMS

Other than that you have to try if it works for you.
If you are able to wait a bit more for a new kernel, PVE 5 will include 4.9 or 4.10 kernel [3]

[1] https://packages.debian.org/jessie-backports/linux-image-4.9.0-0.bpo.1-rt-amd64-unsigned
[2] https://en.wikipedia.org/wiki/Real-time_computing
[3] https://forum.proxmox.com/threads/pve-5-0-eta.33159/#post-162622

 

[ispirto]

This is a Kernel patched with the PREEMPT_RT realtime patch set [1] for realtime [2] support.
In can be wrong as I do not know your use case, but normally this is not needed or wanted on server hardware for virtualization.

Some disadvantages I can think of at the moment would be:
* it's not explicitly tested on Proxmox VE
* realtime patched kernel have also not much exposure to Hypervisor systems running KVM + LXC machines, AFAIK
* If you use ZFS you need to install the module with DKMS

Other than that you have to try if it works for you.
If you are able to wait a bit more for a new kernel, PVE 5 will include 4.9 or 4.10 kernel [3]

[1] https://packages.debian.org/jessie-backports/linux-image-4.9.0-0.bpo.1-rt-amd64-unsigned
[2] https://en.wikipedia.org/wiki/Real-time_computing
[3] https://forum.proxmox.com/threads/pve-5-0-eta.33159/#post-162622

Thank you Thomas.

I'm running the non rt version of the kernel now (4.9.0-0.bpo.1-amd64) and testing it.

I don't use ZFS and this kernel doesn't have the realtime patch. So I guess the only visible risk is that it's not tested with the PVE. Am I correct?

Are there any patches made by Proxmox team on the 4.4.40-1 kernel that are 100% needed for the environment to work properly other than ZFS?

 

[ispirto]

I've found this README file regarding the PVE kernel development: https://git.proxmox.com/?p=pve-kernel.git;a=blob_plain;f=README;hb=HEAD I'm not sure if it's the latest one but it doesn't sound like it's the latest one.

Do you know where I can find the updated README on how you make your kernels such as 4.4.40-1?

 

[fabian]

I've found this README file regarding the PVE kernel development: https://git.proxmox.com/?p=pve-kernel.git;a=blob_plain;f=README;hb=HEAD I'm not sure if it's the latest one but it doesn't sound like it's the latest one.

Do you know where I can find the updated README on how you make your kernels such as 4.4.40-1?

the README is a bit out of date, but not much. just use the included Makefile to build

 

[t.lamprecht]

So I guess the only visible risk is that it's not tested with the PVE. Am I correct?

One thing maybe, we often apply security fixes until they get applied in our upstream Kernel so that we can release them earlier. Also Bug fixes which affect PVE related topics will hit normally our Kernel faster than the more generic used Debian Backported kernel.

Are there any patches made by Proxmox team on the 4.4.40-1 kernel that are 100% needed for the environment to work properly other than ZFS?

No normally there are no patches from us on the kernel which are 100% needed to have a working PVE.