Merge pull request #12046 from asridharan/master

docs/getting-started-guides/docker.md

@@ -55,6 +55,33 @@ Here's a diagram of what the final result will look like:
 ### Prerequisites
 
 1. You need to have docker installed on one machine.
+2. Your kernel should support memory and swap accounting. Ensure that the
+following configs are turned on in your linux kernel:
+
+    ```console
+    CONFIG_RESOURCE_COUNTERS=y
+    CONFIG_MEMCG=y
+    CONFIG_MEMCG_SWAP=y
+    CONFIG_MEMCG_SWAP_ENABLED=y
+    CONFIG_MEMCG_KMEM=y
+    ```
+
+3. Enable the memory and swap accounting in the kernel, at boot, as command line
+parameters as follows:
+
+    ```console
+    GRUB_CMDLINE_LINUX="cgroup_enable=memory swapaccount=1"
+    ```
+
+    NOTE: The above is specifically for GRUB2.
+    You can check the command line parameters passed to your kenel by looking at the
+    output of /proc/cmdline:
+
+    ```console
+    $cat /proc/cmdline
+    BOOT_IMAGE=/boot/vmlinuz-3.18.4-aufs root=/dev/sda5 ro cgroup_enable=memory
+    swapaccount=1
+    ```
 
 ### Step One: Run etcd