diff --git a/docs/cri/config.md b/docs/cri/config.md
index ce86c810b..8dd93dd44 100644
--- a/docs/cri/config.md
+++ b/docs/cri/config.md
@@ -6,7 +6,104 @@ path: `/etc/containerd/config.toml`).
See [here](https://github.com/containerd/containerd/blob/main/docs/ops.md)
for more information about containerd config.
+Note that the `[plugins."io.containerd.grpc.v1.cri"]` section is specific to CRI,
+and not recognized by other containerd clients such as `ctr`, `nerdctl`, and Docker/Moby.
+
+## Basic configuration
+### Cgroup Driver
+While containerd and Kubernetes use the legacy `cgroupfs` driver for managing cgroups by default,
+it is recommended to use the `systemd` driver on systemd-based hosts for compliance of
+[the "single-writer" rule](https://systemd.io/CGROUP_DELEGATION/) of cgroups.
+
+To configure containerd to use the `systemd` driver, set the following option in `/etc/containerd/config.toml`:
+```toml
+version = 2
+[plugins."io.containerd.grpc.v1.cri".containerd.runtimes.runc.options]
+ SystemdCgroup = true
+```
+
+In addition to containerd, you have to configure the `KubeletConfiguration` to use the "systemd" cgroup driver.
+The `KubeletConfiguration` is typically located at `/var/lib/kubelet/config.yaml`:
+```yaml
+kind: KubeletConfiguration
+apiVersion: kubelet.config.k8s.io/v1beta1
+cgroupDriver: "systemd"
+```
+
+kubeadm users should also see [the kubeadm documentation](https://kubernetes.io/docs/tasks/administer-cluster/kubeadm/configure-cgroup-driver/).
+
+### Snapshotter
+
+The default snapshotter is set to `overlayfs` (akin to Docker's `overlay2` storage driver):
+```toml
+version = 2
+[plugins."io.containerd.grpc.v1.cri".containerd]
+ snapshotter = "overlayfs"
+```
+
+See [here](https://github.com/containerd/containerd/blob/main/docs/snapshotters) for other supported snapshotters.
+
+### Runtime classes
+
+The following example registers custom runtimes into containerd:
+```toml
+version = 2
+[plugins."io.containerd.grpc.v1.cri".containerd]
+ default_runtime_name = "crun"
+ [plugins."io.containerd.grpc.v1.cri".containerd.runtimes]
+ # crun: https://github.com/containers/crun
+ [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.crun]
+ runtime_type = "io.containerd.runc.v2"
+ [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.crun.options]
+ BinaryName = "/usr/local/bin/crun"
+ # gVisor: https://gvisor.dev/
+ [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.gvisor]
+ runtime_type = "io.containerd.runsc.v1"
+ # Kata Containers: https://katacontainers.io/
+ [plugins."io.containerd.grpc.v1.cri".containerd.runtimes.kata]
+ runtime_type = "io.containerd.kata.v2"
+```
+
+In addition, you have to install the following `RuntimeClass` resources into the cluster
+with the `cluster-admin` role:
+
+```yaml
+apiVersion: node.k8s.io/v1
+kind: RuntimeClass
+metadata:
+ name: crun
+handler: crun
+---
+apiVersion: node.k8s.io/v1
+kind: RuntimeClass
+metadata:
+ name: gvisor
+handler: gvisor
+---
+apiVersion: node.k8s.io/v1
+kind: RuntimeClass
+metadata:
+ name: kata
+handler: kata
+```
+
+To apply a runtime class to a pod, set `.spec.runtimeClassName`:
+
+```yaml
+apiVersion: v1
+kind: Pod
+spec:
+ runtimeClassName: crun
+```
+
+See also [the Kubernetes documentation](https://kubernetes.io/docs/concepts/containers/runtime-class/).
+
+## Full configuration
The explanation and default value of each configuration item are as follows:
+
+
+
+
```toml
# Use config version 2 to enable new configuration fields.
# Config file is parsed as version 1 by default.
@@ -324,6 +421,9 @@ version = 2
config_path = ""
```
+
+
+
## Registry Configuration
Here is a simple example for a default registry hosts configuration. Set
@@ -344,6 +444,18 @@ server = "https://docker.io"
capabilities = ["pull", "resolve"]
```
+To specify a custom certificate:
+
+```
+$ cat /etc/containerd/certs.d/192.168.12.34:5000/hosts.toml
+server = "https://192.168.12.34:5000"
+
+[host."https://192.168.12.34:5000"]
+ ca = "/path/to/ca.crt"
+```
+
+See [`docs/hosts.md`](https://github.com/containerd/containerd/blob/main/docs/hosts.md) for the further information.
+
## Untrusted Workload
The recommended way to run untrusted workload is to use
diff --git a/docs/cri/registry.md b/docs/cri/registry.md
index 8cff40999..b96714515 100644
--- a/docs/cri/registry.md
+++ b/docs/cri/registry.md
@@ -10,6 +10,13 @@ should now use the form
config_path = "/etc/containerd/certs.d"
```
+- - -
+
+
+
+Show the original content (DEPRECATED)
+
+
## Configure Registry Endpoint
With containerd, `docker.io` is the default image registry. You can also set up other image registries similar to docker.
@@ -193,3 +200,6 @@ Image is up to date for sha256:78096d0a54788961ca68393e5f8038704b97d8af374249dc5
---
NOTE: The configuration syntax used in this doc is in version 2 which is the recommended since `containerd` 1.3. For the previous config format you can reference [https://github.com/containerd/cri/blob/release/1.2/docs/registry.md](https://github.com/containerd/cri/blob/release/1.2/docs/registry.md).
+
+
+
diff --git a/docs/snapshotters/README.md b/docs/snapshotters/README.md
new file mode 100644
index 000000000..d4d892eec
--- /dev/null
+++ b/docs/snapshotters/README.md
@@ -0,0 +1,26 @@
+# Snapshotters
+
+Snapshotters manage the snapshots of the container filesystems.
+
+The available snapshotters can be inspected by running `ctr plugins ls` or `nerdctl info`.
+
+## Core snapshotter plugins
+
+Generic:
+- `overlayfs` (default): OverlayFS. This driver is akin to Docker/Moby's "overlay2" storage driver, but containerd's implementation is not called "overlay2".
+- `native`: Native file copying driver. Akin to Docker/Moby's "vfs" driver.
+
+Filesystem-specific:
+- `btrfs`: btrfs. Needs the plugin root (`/var/lib/containerd/io.containerd.snapshotter.v1.btrfs`) to be mounted as btrfs.
+- `zfs`: ZFS. Needs the plugin root (`/var/lib/containerd/io.containerd.snapshotter.v1.zfs`) to be mounted as ZFS. See also https://github.com/containerd/zfs .
+- `devmapper`: ext4/xfs device mapper. See [`devmapper.md`](./devmapper.md).
+
+[Deprecated](https://github.com/containerd/containerd/blob/main/RELEASES.md#deprecated-features):
+- `aufs`: AUFS. Deprecated since containerd 1.5. Planned to be removed in containerd 2.0. See also https://github.com/containerd/aufs .
+
+## Non-core snapshotter plugins
+
+- `fuse-overlayfs`: [FUSE-OverlayFS Snapshotter](https://github.com/containerd/fuse-overlayfs-snapshotter)
+- `nydus`: [Nydus Snapshotter](https://github.com/containerd/nydus-snapshotter)
+- `overlaybd`: [OverlayBD Snapshotter](https://github.com/containerd/accelerated-container-image)
+- `stargz`: [Stargz Snapshotter](https://github.com/containerd/stargz-snapshotter)
diff --git a/snapshots/devmapper/README.md b/docs/snapshotters/devmapper.md
similarity index 100%
rename from snapshots/devmapper/README.md
rename to docs/snapshotters/devmapper.md