Containers

Introduction

Containers are the default type for LXD and currently the most featureful and complete implementation of LXD instances.

They are implemented through the use of liblxc (LXC).

Configuration

See instance configuration for valid configuration options.

Live migration

LXD supports live migration of containers using CRIU. In order to optimize the memory transfer for a container LXD can be instructed to make use of CRIU’s pre-copy features by setting the migration.incremental.memory property to true. This means LXD will request CRIU to perform a series of memory dumps for the container. After each dump LXD will send the memory dump to the specified remote. In an ideal scenario each memory dump will decrease the delta to the previous memory dump thereby increasing the percentage of memory that is already synced. When the percentage of synced memory is equal to or greater than the threshold specified via migration.incremental.memory.goal LXD will request CRIU to perform a final memory dump and transfer it. If the threshold is not reached after the maximum number of allowed iterations specified via migration.incremental.memory.iterations LXD will request a final memory dump from CRIU and migrate the container.