Linux Tip #1: Max Amount of Locked Memory

This is primarily for Mixbus and Mixbus32c running on Linux. the distro I’m using is Fedora Jam, however this may apply to other distros as well as Ardour, Which Mixbus is based on.

Issue

Mixbus 32c shows the following message when launched:

WARNING: Your system has a limit for maximum amount of locked memory.
This might cause Mixbus32C to run out of memory before your system runs
out of memory.
You can view the memory limit with ‘ulimit -l’, and it is normally controlled by /etc/security/limits.conf
Solution

Open a Terminal window and check the memory limit by typing ulimit -l . You may see something like this:

$ ulimit -l
8192

This means that Mixbus is limited to 8GB of memory. To open this limit up, in Terminal, edit limits.conf:

$ sudo vi /etc/security/limits.conf

Add the following line (ensure there are tabs between each entry and, yes, the – is an entry):

@audio     –     memlock     unlimited

Save the file and check the ulimit again. You should see this:

$ ulimit -l
$ unlimited

Launch Mixbus. If you see the same warning message, check your group in Terminal:

$ groups username

If you don’t see the audio group listed, for example:

username : username wheel pkg-build

add your user to the audio group:

$ sudo usermod -a -G audio username

Check groups again. You should see audio listed:

$ groups username
username : username wheel audio pkg-build

Launch Mixbus and the message should be gone.