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diff --git a/g3doc/user_guide/checkpoint_restore.md b/g3doc/user_guide/checkpoint_restore.md deleted file mode 100644 index 0ab0911b0..000000000 --- a/g3doc/user_guide/checkpoint_restore.md +++ /dev/null @@ -1,101 +0,0 @@ -# Checkpoint/Restore - -[TOC] - -gVisor has the ability to checkpoint a process, save its current state in a -state file, and restore into a new container using the state file. - -## How to use checkpoint/restore - -Checkpoint/restore functionality is currently available via raw `runsc` -commands. To use the checkpoint command, first run a container. - -```bash -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 same directory; every image-path -> provided must be unique. - -```bash -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. - -```bash -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). - -```bash -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. - -Run a container: - -```bash -docker run [options] --runtime=runsc <image>` -``` - -Checkpoint a container: - -```bash -docker checkpoint create <container> <checkpoint_name>` -``` - -Create a new container into which to restore: - -```bash -docker create [options] --runtime=runsc <image> -``` - -Restore a container: - -```bash -docker start --checkpoint --checkpoint-dir=<directory> <container> -``` - -### Issues Preventing Compatibility with Docker - -- **[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 fixed in newer releases. -- **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. -- **[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 |