731e144a48
base_image_size effectively is the limit of a layer size that can be created using the devmapper snapshotter. While this will also depend on the thinpool size itself, something closer to the total image size (80%?) is more appropriate. As is, if you try to run an image like elastic, you'll need a much larger base_image_size than 128MB. Signed-off-by: Eric Ernst <eric.ernst@intel.com>
1.4 KiB
1.4 KiB
Devmapper snapshotter
Devmapper is a containerd snapshotter plugin that stores snapshots in ext4-formatted filesystem images
in a devicemapper thin pool.
Setup
To make it work you need to prepare thin-pool in advance and update containerd's configuration file.
This file is typically located at /etc/containerd/config.toml.
Here's minimal sample entry that can be made in the configuration file:
[plugins]
...
[plugins.devmapper]
pool_name = "containerd-pool"
base_image_size = "8192MB"
...
The following configuration flags are supported:
root_path- a directory where the metadata will be available (if empty default location forcontainerdplugins will be used)pool_name- a name to use for the devicemapper thin pool. Pool name should be the same as in/dev/mapper/directorybase_image_size- defines how much space to allocate when creating the base device
Pool name and base image size are required snapshotter parameters.
Run
Give it a try with the following commands:
ctr images pull --snapshotter devmapper docker.io/library/hello-world:latest
ctr run --snapshotter devmapper docker.io/library/hello-world:latest test
Requirements
The devicemapper snapshotter requires dmsetup (>= 1.02.110) command line tool to be installed and
available on your computer. On Ubuntu, it can be installed with apt-get install dmsetup command.