How to benchmark performance#

The performance of your LXD server or cluster depends on a lot of different factors, ranging from the hardware, the server configuration, the selected storage driver and the network bandwidth to the overall usage patterns.

To find the optimal configuration, you should run benchmark tests to evaluate different setups.

LXD provides a benchmarking tool for this purpose. This tool allows you to initialize or launch a number of containers and measure the time it takes for the system to create the containers. If you run this tool repeatedly with different configurations, you can compare the performance and evaluate which is the ideal configuration.

Get the tool#

If you’re using the snap, the benchmarking tool is automatically installed. It is available as lxd.benchmark.

Otherwise, if you have installed LXD through your distribution’s package manager or built from source, the tool should be available as lxd-benchmark. If it isn’t, make sure that you have go (version 1.18 or later) installed and install the tool with the following command:

go install github.com/lxc/lxd/lxd-benchmark@latest

Run the tool#

Run lxd.benchmark [action] to measure the performance of your LXD setup. (This command assumes that you are using the snap; otherwise, replace lxd.benchmark with lxd-benchmark, also in the following examples.)

The benchmarking tool uses the current LXD configuration. If you want to use a different project, specify it with --project.

For all actions, you can specify the number of parallel threads to use (default is to use a dynamic batch size). You can also choose to append the results to a CSV report file and label them in a certain way.

See lxd.benchmark help for all available actions and flags.

Select an image#

Before you run the benchmark, select what kind of image you want to use.

Local image

If you want to measure the time it takes to create a container and ignore the time it takes to download the image, you should copy the image to your local image store before you run the benchmarking tool.

To do so, run a command similar to the following and specify the fingerprint (for example, 2d21da400963) of the image when you run lxd.benchmark:

lxc image copy images:ubuntu/22.04 local:

You can also assign an alias to the image and specify that alias (for example, ubuntu) when you run lxd.benchmark:

lxc image copy images:ubuntu/22.04 local: --alias ubuntu
Remote image

If you want to include the download time in the overall result, specify a remote image (for example, images:ubuntu/22.04). The default image that lxd.benchmark uses is the latest Ubuntu image (ubuntu:), so if you want to use this image, you can leave out the image name when running the tool.

Create and launch containers#

Run the following command to create a number of containers:

lxd.benchmark init --count <number> <image>

Add --privileged to the command to create privileged containers.

For example:

Command

Description

lxd.benchmark init --count 10 --privileged

Create ten privileged containers that use the latest Ubuntu image.

lxd.benchmark init --count 20 --parallel 4 images:alpine/edge

Create 20 containers that use the Alpine Edge image, using four parallel threads.

lxd.benchmark init 2d21da400963

Create one container that uses the local image with the fingerprint 2d21da400963.

lxd.benchmark init --count 10 ubuntu

Create ten containers that use the image with the alias ubuntu.

If you use the init action, the benchmarking containers are created but not started. To start the containers that you created, run the following command:

lxd.benchmark start

Alternatively, use the launch action to both create and start the containers:

lxd.benchmark launch --count 10 <image>

For this action, you can add the --freeze flag to freeze each container right after it starts. Freezing a container pauses its processes, so this flag allows you to measure the pure launch times without interference of the processes that run in each container after startup.

Delete containers#

To delete the benchmarking containers that you created, run the following command:

lxd.benchmark --delete

Note

You must delete all existing benchmarking containers before you can run a new benchmark.