Heroku: understanding what version of Linux Kernel is used - heroku

I'm confused about which Linux Kernel is used to run Heroku apps, and the docs don't seem to spell it out.
Heroku offers "stacks" synced to Ubuntu LTS releases, and I just upgraded one of our apps from Heroku-18 (Ubuntu 18.04) to Heroku-20 (Ubuntu 20.04), and I was curious as to whether that would constitute a Linux Kernel upgrade.
So, before I upgraded the stack, I logged into a dyno and ran the following (on Heroku-18):
~ $ cat /proc/version_signature
Ubuntu 4.4.0-1097.102-aws 4.4.262
~ $ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.6 LTS
Release: 18.04
Codename: bionic
and then after upgrading to Heroku-20:
~ $ cat /proc/version_signature
Ubuntu 4.4.0-1097.102-aws 4.4.262
~ $ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.3 LTS
Release: 20.04
Codename: focal
So, upgrading did NOT change the Kernel version 4.4.262, which appears to have been released March 2021 (10 months ago).
The docs for Ubuntu 20 say that it's based on LTS Linux 5.4, so why is Heroku continuing to use the older 4.4.x Kernel? When might this be upgraded, and how might it be communicated?
I was also curious what the Kernel version would be for Heroku's container stack; I'm not sure how to find this out, but given the above, I'm betting that it too would be 4.4.x. This matters to me because I'm curious to try out io_uring and some other recent Linux Kernel developments, but it seems like I'd have to wait a long time to try out something like that on Heroku.

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install linux distribution under wsl [migrated]

This question was migrated from Stack Overflow because it can be answered on Super User.
Migrated 25 days ago.
I am trying to use WSL under Windows 10 Pro, and while WSL itself was installed without a problem, I cannot install any Linux distribution under it.
PS C:\WINDOWS\system32> wsl --version
WSL version: 1.0.3.0
Kernel version: 5.15.79.1
WSLg version: 1.0.47
MSRDC version: 1.2.3575
Direct3D version: 1.606.4
DXCore version: 10.0.25131.1002-220531-1700.rs-onecore-base2-hyp
Windows version: 10.0.19042.2486
PS C:\WINDOWS\system32> wsl -l
Windows Subsystem for Linux has no installed distributions.
Use 'wsl.exe --list --online' to list available distributions
and 'wsl.exe --install <Distro>' to install.
Distributions can also be installed by visiting the Microsoft Store:
https://aka.ms/wslstore
Error code: Wsl/WSL_E_DEFAULT_DISTRO_NOT_FOUND
PS C:\WINDOWS\system32> wsl -l -o
The following is a list of valid distributions that can be installed.
Install using 'wsl.exe --install <Distro>'.
NAME FRIENDLY NAME
Ubuntu Ubuntu
Debian Debian GNU/Linux
kali-linux Kali Linux Rolling
SLES-12 SUSE Linux Enterprise Server v12
SLES-15 SUSE Linux Enterprise Server v15
Ubuntu-18.04 Ubuntu 18.04 LTS
Ubuntu-20.04 Ubuntu 20.04 LTS
Ubuntu-22.04 Ubuntu 22.04 LTS
OracleLinux_8_5 Oracle Linux 8.5
OracleLinux_7_9 Oracle Linux 7.9
PS C:\WINDOWS\system32> wsl --install Ubuntu
Installing: Ubuntu
Error: 0x80244018 0.0% ]
Error code: Wsl/InstallDistro/0x80244018
PS C:\WINDOWS\system32> wsl --install Debian
Installing: Debian GNU/Linux
Error: 0x80244018 0.0% ]
Error code: Wsl/InstallDistro/0x80244018
PS C:\WINDOWS\system32>
I did try disabling proxy, as I found in one of the posts, but instead of Error: 0x80244018 got Catastrophic Failure.
Can anybody recommend what I can do to install a distro?
As I believe you've discovered (from your proxy comment), this error is usually due to a failure in the Windows Update service. By default, WSL uses this service to install distributions from the Microsoft Store, but many other Windows components and applications use the service as well.
While the information below may help with WSL, it's likely that you have a more significant issue that you'll need to resolve. If that's the case, you'll probably want to post a new question that is broader in scope, rather than just this one that focuses on WSL.
That said, my suggested workaround for installing WSL distributions would be to try:
wsl --install --web-download Debian
The --web-download option skips the Store (and shouldn't use the Windows Update service), and will download the distribution directly then install it.
Alternatively, if you can get access to a working Docker installation apart from this system, you could use the steps found in Import any Linux distribution to use with WSL.

Upgradation of centos/redhat from 5.x to 6.x

Trying to upgrade Linux Centos/Redhat from 5.x to 6.x version without formatting the os,
need to know any steps for the upgrade from 5.x to 6.x
Based on this, you can simply run the flowing command to upgrade distribution and kernel:
# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 6.9 (Santiago)
# arch
x86_64
# yum upgrade -y

VMWare 12.5 doesn't like my gcc-6 under Mint

I'm spending way too muhc time on trying to figure this out, so I decided to ask you guys for a little help.
I downloaded VMWare Workstation 12.5.5 on kernel 4.10.8 (Linux Mint 18.1).
A popup show up saying I don't have gcc >= 6.2.0.
After trying to compile it I realised there's a version hosted on a ppa:
deb http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu xenial
main
sudo apt update
sudo apt install gcc-6
I relaunch vmware and I still get this error. Entering the path manually to /usr/bin/gcc-6 doesn't work either. /usr/bin/gcc-6 -v gives me gcc version 6.2.0 20160901 (Ubuntu 6.2.0-3ubuntu11~16.04)
How can I run VMware on my machine? Thanks! :D

What OS does heroku cedar run?

I had though cedar was running on Ubuntu 10.04, but when checking it seems this is not the case:
heroku run python
from platform import platform
platform()
'Linux-3.8.11-ec2-x86_64-with-debian-squeeze-sid'
A binary I previously compiled on 10.04 and ran happily on heroku is now segfaulting, so I'd like to work out what stack to compile against.
It's Ubuntu 10.04, here's the output from heroku run bash
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 10.04 LTS
Release: 10.04
Codename: lucid
Based on their documentation, it is running Ubuntu 10.04
They are now running Ubuntu 14.04 :
https://devcenter.heroku.com/articles/stack#cedar
In one line (based on John Beynon's answer ):
heroku run "lsb_release -a"
Response:
...
Description: Ubuntu 18.04.4 LTS

libvirt and VirtualBox on OS X

I'm trying to access VirtualBox through libvirt on OS X (Lion). I installed libvirt 0.9.4 using Homebrew. However, libvirt fails to connect to VirtualBox:
# virsh -c vbox:///session
error: internal error unable to initialize VirtualBox driver API
error: failed to connect to the hypervisor
In a similar SO question about Ubuntu, the answer was that the Ubuntu libvirt package doesn't build support for VirtualBox. How can I check if this is the problem in the case of the Homebrew package, or if it's a different issue? If it's the same problem, how do I rebuild the Homebrew package with VirtualBox support?
Edit: libvirt 0.9.7 has been released, and I no longer get this error.
Your libvirt is build with VirtualBox support. I can tell because the error message you see comes from the VirtualBox driver in libvirt.
There was a similar problem reported on the libvirt users maling list today. The problem there was that support for VirtualBox 4.1 was added quite recently to libvirt. It's not in a released version yet and will be part of the next libvirt release 0.9.7.
To get some more useful information try running this:
LIBVIRT_LOG_FILTERS=1:vbox virsh -c vbox:///session
I suspect that you have VirtualBox 4.1 installed, but libvirt 0.9.4 supports only up to VirtualBox 4.0.
You can either a) upgrade your libvirt to current git version (that supports VirtualBox 4.1), or b) wait for the next libvirt release (it's expected in this week) or c) downgrade your VirtualBox version to 4.0 to fix this, assuming your problem is really as I suspect.

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