chef-btrfs_snap

Description

Cookbook for Opscode chef to make snapshots of btrfs filesystems using btrfs-snap:

https://github.com/jf647/btrfs-snap

Attributes

Configuration

These attributes are under the node['btrfs_snap'] namespace.

Attribute	Description	Type	Default
install_dir	Where to install btrfs-snap	String	/opt/btrfs-snap
btrfs_prog	Path to btrfs program	String	/sbin/btrfs
snapshot_basedir	Base directory for snapshots	String	/snapshots
snapshot_basedir_owner	Owner of base directory	String	root
snapshot_basedir_group	Group of base directory	String	root
snapshot_basedir_mode	Mode of base directory	Number	0755
git_url	URL to clone btrfs-snap from	String	https://github.com/jf647/btrfs-snap.git
git_ref	Git ref to use in btrfs-snap repo	String	master
rootmount	The subvolid=5 mount of the btrfs filesystem	String	/btrfs
enable_periodic_scrub	Whether to perform periodic scrubs of the btrfs filesystem	Boolean	false
periodic_scrub_schedule	The schedule to perform scrubs on	Hash	{ 'weekday' => 4, 'minute' => 30, 'hour' => 2 }
snapshots	Snapshots to take	Hash	none (see below)

Snapshots

This attribute-driven snapshot recipe is rather opinionated about snapshot schedules. This provides ease of use at the cost of flexibility. Pull requests are welcome for additional schedules or alternate approaches.

There are several named schedules. Each one corresponds to a period, a number of generations to keep and where the snapshot is kept:

Schedule Name	Period	Generations to Keep	Location
10_minutes	every minute	10	Inside Filesystem
1_hour	every 5 minutes	12	Basedir
1_day_fast	every hour at 3 minutes past	24	Basedir
1_day_slow	every 3 hours at 6 minutes past	8	Basedir
1_week	every day at 00:09	7	Basedir
2_weeks	every day at 00:12	14	Basedir
3_months	every Sunday at 00:15	12	Basedir
6_months	first day of every month at 00:18	6	Basedir
1_year	first day of every 3rd month at 00:21	4	Basedir

Each filesystem that you want snapshots of needs an entry under the node['btrfs_snap']['snapshots'] namespace:

{
   "btrfs_snap" : {
      "snapshots" : {
         "etc" : {
            "mount" : "/etc",
            "schedule" : [
               "10_minutes",
               "2_weeks"
            ]
         },
         "var" : {
            "mount" : "/var",
            "schedule" : [
               "1_day_slow",
               "1_week"
            ]
         },
         "root" : {
            "mount" : "/",
            "schedule" : [
               "1_day_slow",
               "1_week"
            ]
         },
         "home_james" : {
            "mount" : "/home/james",
            "schedule" : [
               "10_minutes",
               "1_day_slow",
               "2_weeks"
            ]
         }
      }
   }
}

Each filesystem can have more than one schedule. Each schedule is turned into a cronjob.

Recipes

• recipe[btrfs_snap::install] Installs btrfs-snap
• recipe[btrfs_snap::snapshot] Makes snapshots based on node attributes
• recipe[btrfs_snap::scrub] Performs periodic scrub of btrfs filesystem
• recipe[btrfs_snap::default] Combines install, snapshot and scrub

LWRPs

• btrfs_snap_snapshot - Snapshots a btrfs filesystem on one or more schedules

Attribute	Description	Type	Default
mount	Filesystem to snapsot	String
schedule	Schedules to snapshot at	Array
readonly	Whether snapshot should be readonly	Boolean	true
basedir	Where to make the snapshot	String	/snapshots

Usage

Install btrfs-snap

Add recipe[btrfs_snap::install] to your node's run list.

Take Snapshots based on Attributes

Add recipe[btrfs_snap::snapshot] to your node's run list. Configure one or more snapshots as described above.

Take a Snapshot

In a recipe:

include_recipe 'btrfs'

btrfs_snap_snapshot "name" do
    mount "/etc"
    schedule [ '1_week', '3_months' ]
    readonly false
    basedir "/foo"
end

Perform a Periodic Filesystem Scrub

In order to perform a scrub, you have to have the root of your btrfs filesystem mounted somewhere. Typically this is done with a line in fstab like this:

UUID=XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX   /btrfs   btrfs   defaults,subvolid=5   0   0

Add recipe[btrfs_snap::scrub] to your node's run list. Set node['btrfs_snap']['enable_periodic_scrub'] to true and if desired, change node['btfs_snap']['periodic_scrub_schedule'] to suit your needs. If you mount the root of your btrfs filesystem somewhere other than /btrfs, modify node['btrfs_snap']['rootmount'] as needed.

License

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Authors

• Copyright (c) 2013 James FitzGibbon james@nadt.net