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diff --git a/runsc/checkpoint_restore.md b/runsc/checkpoint_restore.md deleted file mode 100644 index 5fa3280a8..000000000 --- a/runsc/checkpoint_restore.md +++ /dev/null @@ -1,108 +0,0 @@ -# runsc checkpoint/restore - -gVisor supports checkpointing and restoring containers. A container’s state can -be checkpointed and later restored into one or more containers. This can be used -to save work and time in cases of failure and allow for container migration. A -single container can perform slower setup tasks and then be checkpointed so that -many containers with the same task can be “restored” and started more quickly. - -### How to checkpoint/restore - -To use the runsc checkpoint command, first run a container. - -```sh -runsc run <container id> -``` - -To checkpoint the container, the --image-path flag must be provided. This is the -directory path within which the checkpoint state-file will be created. The file -will be called checkpoint.img and necessary directories will be created if they -do not yet exist. - -> Note: Two checkpoints cannot be saved to the save directory; every image-path -provided must be unique. - -```sh -runsc checkpoint --image-path=<path> <container id> -``` - -There is also an optional --leave-running flag that allows the container to -continue to run after the checkpoint has been made. (By default, containers stop -their processes after committing a checkpoint.) - -> Note: All top-level runsc flags needed when calling run must be provided to -checkpoint if --leave-running is used. - -> Note: --leave-running functions by causing an immediate restore so the -container, although will maintain its given container id, may have a different -process id. - -```sh -runsc checkpoint --image-path=<path> --leave-running <container id> -``` - -To restore, provide the image path to the checkpoint.img file created during the -checkpoint. Because containers stop by default after checkpointing, restore -needs to happen in a new container (restore is a command which parallels start). - -```sh -runsc create <container id> - -runsc restore --image-path=<path> <container id> -``` - -### How to use checkpoint/restore in Docker: - -Currently checkpoint/restore through runsc is not entirely compatible with -Docker, although there has been progress made from both gVisor and Docker to -enable compatibility. Here, we document the ideal workflow. - -To run with Docker, first follow the [instructions](https://gvisor.googlesource.com/gvisor/+/master/README.md#configuring-docker) to use runsc as a runtime. - -Run a container: - -```sh -docker run [options] --runtime=runsc <image>` -``` - -Checkpoint a container: - -```sh -docker checkpoint create <container> <checkpoint_name>` -``` - -Create a new container into which to restore: - -```sh -docker create [options] --runtime=runsc <image> -``` - -Restore a container: - -```sh -docker start --checkpoint --checkpoint-dir=<directory> <container> -``` - -**Issues Preventing Compatibility with Docker** -1. [Moby #37360][leave-running] - -Docker version 18.03.0-ce and earlier hangs when checkpointing and -does not create the checkpoint. To successfully use this feature, install a -custom version of docker-ce from the moby repository. This issue is caused by an -improper implementation of the `--leave-running` flag. This issue is now fixed -although is not yet part of an official release. - -2. Docker does not support restoration into new containers. - -Docker currently expects the container which created the checkpoint -to be the same container used to restore which is not possible in runsc. When -Docker supports container migration and therefore restoration into new -containers, this will be the flow. - -3. [Moby #37344][checkpoint-dir] - -Docker does not currently support the `--checkpoint-dir` flag but this will be -required when restoring from a checkpoint made in another container. - -[leave-running]: https://github.com/moby/moby/pull/37360 -[checkpoint-dir]: https://github.com/moby/moby/issues/37344 |