[backup] Add btrfs_snapshot_date.sh

Makes a dated snapshot with Btrfs.

backup/README

@@ -8,6 +8,21 @@ The transfer will be reattempted until it succeed.
 Edit the script to configure the protocol, host, directories, etc.
 
 
+# btrfs_snapshot_date.sh #
+
+This script is a wrapper to btrfs subvolume snapshot, that creates a
+snapshot of a subvolume, the snapshot's name being the subvolume name
+with the current date and time appended to it.
+
+It is supposed that the subvolume to snapshot resides in a directory
+which needs to be mounted before to make the snapshot (for example if
+you defined your default subvolume to your system's root, and mount the
+volume 0 on /media/pool).
+
+Edit the script to configure the directories (and to understand what is
+being done).
+
+
 # backup_sites_mysql.sh #
 
 The script backup_sites_mysql.sh is designed to save websites data files

backup/btrfs_snapshot_date.sh

@@ -0,0 +1,22 @@
+#!/bin/sh
+#
+# btrfs_snapshot_date.sh, Copyright © 2011 Matteo Cypriani <mcy@lm7.fr>
+#
+# This program is free software. It comes without any warranty, to
+# the extent permitted by applicable law. You can redistribute it
+# and/or modify it under the terms of the Do What The Fuck You Want
+# To Public License, Version 2, as published by Sam Hocevar. See
+# http://sam.zoy.org/wtfpl/COPYING for more details.
+#
+# Makes a snapshot of a Btrfs subvolume with the date appended to its
+# name.
+
+# Mount point of the Btrfs root volume (in which the subvolumes
+# reside):
+ROOT=/media/pool
+# Name of the subvolume to snapshot:
+SV="backupsv"
+
+mount "$ROOT"
+SV="$ROOT/$SV"
+btrfs subvolume snapshot "$SV" "$SV"_$(date '+%Y-%m-%dT%H:%M:%S')