Update docs to reflect what's going to be implemented

README.md

@@ -24,11 +24,21 @@ from within your `Vagrantfile`:
 Vagrant.configure("2") do |config|
   config.vm.box = 'your-box'
   if Vagrant.has_plugin?("vagrant-cachier")
+    # Enable cache buckets auto detection
     config.cache.auto_detect = true
-    # If you are using VirtualBox, you might want to enable NFS for shared folders
+
-    # config.cache.enable_nfs  = true
+    # If you are using VirtualBox, you might want to use that to enable NFS for
-    # You can pass extra mount options, for example:
+    # shared folders. This is also very useful for vagrant-libvirt if you want
-    # config.cache.sync_opts = {:create = true}
+    # bi-directional sync
+    config.cache.synced_folder_opts = {
+      type: 'nfs',
+      # The nolock option can be useful for an NFSv3 client that wants to avoid the
+      # NLM sideband protocol. Without this option, apt-get might hang if it tries
+      # to lock files needed for /var/cache/* operations. All of this can be avoided
+      # by using NFSv4 everywhere. Please note that the tcp option is not the default.
+      mount_options = ['rw', 'vers=3', 'tcp', 'nolock']
+    }
+    # For more information please check http://docs.vagrantup.com/v2/synced-folders/basic_usage.html
   end
 end
 ```
@@ -43,6 +53,7 @@ http://fgrehm.viewdocs.io/vagrant-cachier.
 * [vagrant-lxc](https://github.com/fgrehm/vagrant-lxc)
 * [VMware providers](http://www.vagrantup.com/vmware) with NFS enabled (See
   [GH-24](https://github.com/fgrehm/vagrant-cachier/issues/24) for more info)
+* [vagrant-libvirt](https://github.com/pradels/vagrant-libvirt)
 
 
 ## Contributing

docs/index.md

@@ -24,9 +24,24 @@ from within your `Vagrantfile`:
 Vagrant.configure("2") do |config|
   config.vm.box = 'your-box'
   if Vagrant.has_plugin?("vagrant-cachier")
+    # Enable cache buckets auto detection
     config.cache.auto_detect = true
-    # If you are using VirtualBox, you might want to enable NFS for shared folders
+
-    # config.cache.enable_nfs  = true
+    # You can pass in extra mount options for your cache buckets
+    # from http://docs.vagrantup.com/v2/synced-folders/basic_usage.html
+    config.cache.synced_folder_opts = { create: true }
+
+    # If you are using VirtualBox, you might want to use that to enable NFS for
+    # shared folders. This is also very useful for vagrant-libvirt if you want
+    # bi-directional sync
+    config.cache.synced_folder_opts = {
+      type: 'nfs',
+      # The nolock option can be useful for an NFSv3 client that wants to avoid the
+      # NLM sideband protocol. Without this option, apt-get might hang if it tries
+      # to lock files needed for /var/cache/* operations. All of this can be avoided
+      # by using NFSv4 everywhere. Please note that the tcp option is not the default.
+      mount_options = ['rw', 'vers=3', 'tcp', 'nolock']
+    }
   end
 end
 ```
@@ -40,6 +55,7 @@ For more information please check out the links on the menu above.
 * [vagrant-lxc](https://github.com/fgrehm/vagrant-lxc)
 * [VMware providers](http://www.vagrantup.com/vmware) with NFS enabled (See
   [GH-24](https://github.com/fgrehm/vagrant-cachier/issues/24) for more info)
+* [vagrant-libvirt](https://github.com/pradels/vagrant-libvirt)
 
 
 ## Contributing

docs/usage.md

@@ -4,9 +4,9 @@
 
 This is the easiest way to get started with plugin. By adding the code below to
 your `Vagrantfile` you can enable automatic detection of supported cache _buckets_.
-It is a good practise to wrap plugin specific configuration with `has_plugin?` checks
+It is a good practice to wrap plugin specific configuration with `has_plugin?` checks
-so the user's Vagrantfiles do not break if plugin is uninstalled or Vagrantfile shared
+so the user's Vagrantfiles do not break if vagrant-cachier is uninstalled or
-with people not having the plugin installed.
+the Vagrantfile is shared with people that do not have the plugin installed.
 
 ```ruby
 Vagrant.configure("2") do |config|
@@ -17,7 +17,7 @@ Vagrant.configure("2") do |config|
 end
 ```
 
-This will make vagrant-cachier do its best to find out what is supported on the
+This will make `vagrant-cachier` do its best to find out what is supported on the
 guest machine and will set buckets accordingly.
 
 ## Enable buckets as needed
@@ -35,6 +35,28 @@ end
 _Please refer to the "Available Buckets" menu above to find out which buckets
 are supported._
 
+## Custom cache buckets synced folders options
+
+For fine grained control over the cache bucket synced folder options you can use
+the `synced_folder_opts` config. That's useful if, for example, you are using
+VirtualBox and want to enable NFS for improved performance:
+
+```ruby
+Vagrant.configure("2") do |config|
+  config.cache.synced_folder_opts = {
+    type: 'nfs',
+    # The nolock option can be useful for an NFSv3 client that wants to avoid the
+    # NLM sideband protocol. Without this option, apt-get might hang if it tries
+    # to lock files needed for /var/cache/* operations. All of this can be avoided
+    # by using NFSv4 everywhere. Please note that the tcp option is not the default.
+    mount_options = ['rw', 'vers=3', 'tcp', 'nolock']
+  }
+end
+```
+
+Please referer to http://docs.vagrantup.com/v2/synced-folders/basic_usage.html for
+more information about the supported parameters.
+
 ## Cache scope
 
 By default downloaded packages will get stored on a folder scoped to base boxes