@yariplus @JasperNL, alternatively you can use Kimsufi, which belongs to OVH to 100%. The only difference is that the systems there are dedicated ones and not virtual machines. I also use one of these for my download server, which works quite alright.
About Redis:
The database size itself will increase the same way as others. More data = bigger database. For more infos check this out:
http://redis.io/topics/faq
