Hyper-V – Made For Cloud

Getting WSL2 just right

gocallag — Sun, 30 Jun 2024 04:03:35 +0000

Recent changes to WSL2 by Microsoft have made using Linux on Windows even more comfortable. I’ll describe some of the options and their use below.

Firstly, do you have WSL2 installed? If not, then this will help https://learn.microsoft.com/en-us/windows/wsl/install-manual#step-1—enable-the-windows-subsystem-for-linux

In order to best use WSL, you of course need to have a distribution installed. Ubuntu is one of the easiest and most common to install.

wsl --list --online           #check what distros are available
wsl --install -d Ubuntu-24.04 #latest at the time of writing

Now that you have a distro installed, we have something to configure. There are 2 configuration files that customise the distribution experience under WSL2. wsl.conf and .wslconfig

wsl.conf contains per-distribution settings, whereas .wslconfig configures global settings for the WSL2 environment.

wsl.conf is stored in the /etc directory within the distribution.

.wslconfig is stored in your %UserProfile% folder.

.wslconfig

The .wslconfig file is in .ini format with the GA features found under section [wsl2]. There is also an [experimental] section for unreleased options.

Note: All options may not be available to you as they are Windows OS and WSL version dependent. You can reasonably assume if you are running Windows 11, 22H2 or higher that most of the options described below are available to you. This is not the complete list, just the one’s I have found to be quite useful

GA features that I find useful

Accessible via the [wsl2] section of the .wslconfig file

Key	Value	Notes
memory	memory size (Mb, Gb)	Default is 50% of the windows memory. I find it useful to constrain the memory (in conjunction with the experimental memory release features below)
processors	number	Default is the same as present in windows
localhostForwarding	true/false	Default is true, this allows your WSL2 application to be accessible via localhost:port
nestedVirtualization	true/false	Allow nesting inside WSL2, Windows 11+
networkingMode	string, NAT, mirrored	The default is NAT, mirrored turns on mirrored networking mode. Mirrored mode is a great addition for many of my use cases.
firewall	true / false	Hyper-V firewall can filter WSL network traffic
dnsTunneling	false	see the experimental section

Some of the GA features

Experimental (though very useful) features

Accessible via [experimental] section of the .wslconfig file.

Key	Value	Notes
autoMemoryReclaim	disabled	Default is disabled, but options list gradual and dropcache can dramatically return memory outside wsl2. I default to gradual.
sparseVHD	false	When set to true new VHD’s are created as sparse saving considerable disk with all the overprovisioning issues. By default, i’m using sparse, but then again i’ve been using sparse filesystems for many years
useWindowsDnsCache	false	If you have dnsTunneling turned on then this option allows you to use or ignore what windows dns may’ve cached
hostAddressLoopback	false	if networkingMode is set to mirrored then the loopback 127.0.0.1 address can be used to access the host and the container depending on where the listening resource may be running – windows or wsl2. This is a great option if you want better sharing between windows and wsl2 distro. For example, i’ve had a mongo client on windows and mongo in wsl2 ubuntu.

Some of the Experimental features

wsl.conf

As I mentioned above the /etc/wsl.conf within the distribution controls some interesting behaviours, especially on distro launch.

[boot]

systemd=true

Solves the problem where you’re reliant on systemd resources within your WSL2 distro. I normally have it turned on.

[automount]

Key	Value	Notes
enabled	true / false	Allows windows fixed drives to be automatically mounted under /mnt (or where the root key points). I have this enabled by default
root	/mnt	Where the mounts occur for auto mounted systems
mountFsTab	true/false	Allow the /etc/fstab to be processed at WSL distro boot time. Great to get those SMB/NFS mounts going. I have this set to true as I use a lot of NFS in my test environment.

Some things to note.

Windows disks are mounted using Drvfs and are by default case sensitive. You can override this behaviour for all or single drives. More information is available at Per-directory case sensitivity and WSL – Windows Command Line (microsoft.com)

[network]

Key	Value	Notes
generateHosts	true/false	wsl will generate an appropriate /etc/hosts file based on the windows environment. I generally set this to true (the default).
generateResolvConf	true/false	wsl will generate an appropriate list of dns resolvers. I generally set this to true (the default).
hostname	string	This sets the hostname to be used within the distro. The default is the windows hostname, but this is useful if you run multiple WSL instances.

Milestone 0.1.5 for Hyper-V ansible collection

gocallag — Mon, 10 Jun 2024 01:53:51 +0000

Milestone 0.1.5 has been achieved for the gocallag.hyperv collection which you can find in ansible galaxy at Ansible Galaxy – gocallag.hyperv.

Release notes for 0.1.5 can be found over at github at Release Milestone 0.1.5 · gocallag/hyperv (github.com)

Further information on upcoming milestones and their associated features can be found at Milestones – gocallag/hyperv (github.com)

What’s Changed

Added Feature to vm_info to provide search capability by Name
Closed Issue 2 – Feature to allow vm info to search by power state and names
BugFIX: Use the convertto-json , convertfrom-json to avoid loop in Exit-Json (limiting depth)
Closed Test Issue: Added verifier for vm_info module checks and cleanups
Closed Test Issue: Added basic asserts for switch_info testing via molecule
Closed Test Issue: Added verifier asserts for switch module as part of molecule testing
Closed Test Issue: Added assert based testing for vm module as part of molecule
BugFIX, Issue 12: bug vm info fails molecule verifier on running vm check

Feedback / Requests welcome.

Ansible Collection for hyperv management

gocallag — Sat, 01 Jun 2024 00:58:19 +0000

Just a quick blog post about a small ansible collection i’m developing to manage my hyperv lab vm’s.

You can find it over at gocallag/hyperv (github.com)

Hyper-V force shutdown VM

gocallag — Sat, 18 May 2024 05:05:10 +0000

Let’s face it, sometimes a Hyper-V gets stuck in a funny state and you can’t shut it down from the UI. Fear not, you can easily force it down using powershell.

Firstly, get the guid of the VM.

$VMID = (Get-VM '





Then, find the process that’s running that VM.



$VMProcess = (Get-WMIObject Win32_Process | ? {$_.Name -match 'VMWP' -and $_.CommandLine -match $VMID})



Then you can force stop that process.



Stop-Process ($VMProcess.ProcessId) –Force



Hey presto, the VM should be down.



Hyper-V set display resolution
gocallag — Sat, 18 May 2024 04:54:16 +0000

With all the migration from VMware to other sources, Hyper-V is making quite a comeback. Hyper-V is a lot better than the good (aka bad) old days, but you still need to know how to handle certain quirks.



In this case I needed to change the resolution of my Hyper-V windows guest to something higher as it was stuck on the default 1152×864.



It’s simple to fix, just shutdown your VM in the Hyper-V manager (or use powershell) and when the system is down, open a powershell window and use.



Set-VMVideo -VMName "" -HorizontalResolution 1920 -VerticalResolution 1080 -ResolutionType Single



Then when you power the VM back on and access via the Hyper-V display option you will have a VM with the larger screen resolution.



Hyper-V meet RHEL8 – screen resolution
gocallag — Wed, 30 Oct 2019 23:44:29 +0000
I’m running Hyper-V on my laptop and I’m also doing work with RHEL 8 desktops. Alas, the default screen resolution you get is the rather odd 1152×864. In order to make this more reasonable, such as the 1920×1080 full screen resolution on my laptop you have to set the hyper-v framebuffer at boot time. You’ll…Continue reading →