How to Resolve High RAM Usage by Vmmem.exe When Running Docker on WSL
Tags: docker, wsl2, memory, vmmem
Published: 2023-10-17 13:59:31

In the world of software development, occasional slowdowns and resource bottlenecks are par for the course. However, there are times when one process, in particular, seems to take an insatiable bite out of your precious RAM. If you’ve ever wondered why a process called Vmmem.exe is consuming an inordinate amount of memory, read on to discover a common culprit and how to tame it.
 
**The Annoying Symptoms**
Picture this: you’re diligently working on your Azure IoT Edge modules when your trusty development laptop begins to exhibit some unusual sluggishness. It’s not entirely unexpected; you often juggle multiple Chrome tabs and Electron apps, pushing your machine’s limits. But today, something different happens. Microsoft Teams starts misbehaving, repeatedly crashing and restarting in a never-ending loop. That’s when you decide it’s time to investigate.

**The Investigation**
You begin your investigation by opening Task Manager, expecting to see the usual suspects like Chrome and Electron apps gobbling up your memory. However, the sight that greets you is far from normal. A staggering 28 GB of RAM usage stares back at you, even though you’re not running a full SharePoint farm on your laptop. Clearly, something is amiss, and it’s not just OneDrive acting up.

**Unmasking the Culprit**
Digging deeper into Task Manager reveals the real villain: Vmmem.exe. It’s consuming an alarming amount of RAM, making even Chrome pale in comparison. But what is Vmmem.exe, and why is it behaving so irrationally?

**The Root Cause**
The culprit, as it turns out, is Windows Subsystem for Linux (WSL) misbehaving. Vmmem.exe represents the memory allocation for your Virtual Machines (VMs), and in your case, it’s closely tied to running Docker containers as part of your development workflow.

Here’s the catch: WSL tends to reserve a significant amount of memory, even if it doesn’t actually need it. In some Windows builds, it can eat up to 80% of your available memory. While this has been improved in later builds, it can still be quite resource-intensive, especially when running alongside applications like Teams and Chrome.

# The Solution
The good news is that resolving this memory consumption issue is straightforward. Here’s how you can do it:

## Step 1: Shut Down WSL
First, let’s free up some resources by shutting down WSL. Open your command line and run the following command:
```
wsl --shutdown
```
## Step 2: Locate Your .wslconfig File

Next, you’ll need to locate the configuration file for WSL. Navigate to %UserProfile% (paste this in the Windows Explorer address bar) and check if you have a .wslconfig file. If it's not there, don't worry; you can create one.

## Step 3: Edit Your .wslconfig File
Edit the .wslconfig file (or create one if it doesn't exist) and add the following configuration to limit memory usage:
```
[wsl2]
memory=2GB
```
Feel free to adjust the memory limit to suit your needs.

## Step 4: Restart Docker (If Applicable)
If you were using Docker, restart it to ensure it recognizes the new configuration. For other workloads dependent on WSL, simply start them, and they should pick up the new settings.

That’s it! You’ve tamed Vmmem.exe and reclaimed your precious RAM. Have you encountered this issue before, and did these steps help? Share your experience in the comments below.