ちょっと kobito からの投稿テストを兼ねて。
EC2 は EBS ボリュームの snapshot 取っておけばバックアップになるので以前書いたスクリプト。

class AWSBackuper(object):
    def __init__(self, access_key, secret_key, region="ap-northeast-1"):
        self.access_key = access_key
        self.secret_key = secret_key
        self.region = region
        self.set_ec2connection()

    def set_ec2connection(self):
        self.ec2connection = boto.ec2.connect_to_region(self.region, aws_access_key_id=self.access_key, aws_secret_access_key=self.secret_key)

    def create_snapshot(self, volume_id, description=None):
        self.ec2connection.create_snapshot(volume_id, description)

    def rotate_snapshot(self, volume_id, num):
        snapshot = {}
        for x in self.ec2connection.get_all_snapshots():
            if(x.volume_id == volume_id):
                tmp = {x.id:x.start_time}
                snapshot.update(tmp)

        snapshot = sorted(snapshot.items(), key=lambda (k, v): (v, k), reverse=True)
        for i in range(int(num), len(snapshot)):
            try:
                self.ec2connection.delete_snapshot(snapshot[i][0])
            except:
                continue

    def add_tags_to_snapshot(self, volume_id):
        tags = self.ec2connection.get_all_volumes(volume_id)[0].tags

        for snapshot in self.ec2connection.get_all_snapshots():
            if(snapshot.volume_id == volume_id):
                for key, value in tags.items():
                    snapshot.add_tag(key, value)

if __name__ == '__main__':

    execfile(sys.argv[1])
    backuper = AWSBackuper(access_key, secret_key)

    for volume_id in volume_ids:
        backuper.create_snapshot(volume_id, 'auto backup')
        print "%s is backed up." % (volume_id)
        backuper.rotate_snapshot(volume_id, generation_limit)
        print "%s is rotated snapshots." % (volume_id)
        backuper.add_tags_to_snapshot(volume_id)
        print "%s is added tags." % (volume_id)

このスクリプトは config ファイルとなる python スクリプトを指定して起動する。

# your volume_ids 
access_key, secret_key = 'YOUR ACCESS KEY', 'YOUR SECRET KEY'
volume_ids = [
    'vol-target-id1',
    'vol-target-id2',
    'vol-target-id3',
]
generation_limit = 7

あとはこんなふうに起動するだけ

python ebs-backuper.py config.py