Right from the start "suspend to RAM" was one of yaVDRs most beloved features giving our users the possibility to start their VDR within a few seconds. While this worked great for a lot of hardware, there were still some configurations where it didn't. That's why we decided to improve the situation by choosing a different method for yaVDR 0.3: "Userspace Software Suspend".

Looking at the methods for suspending/hibernating a Linux PC you'll soon find out that there is more than just one way to go. One is the built-in "kernel" method. That's the way Ubuntu developers chose to go and we followed them with previous versions of yaVDR. One of the other methods is called "Userspace Software Suspend" or -in short- "uswsusp" ( see also http://suspend.sourceforge.net/intro.shtml). The software package consists of two programs named "s2ram" and "s2disk". yaVDR 0.3 makes use of both to implement two methods of suspending/hibernating. You can choose between them in the "shutdown method" tab of yaVDRs webfrontend.

The first is called "Suspend to RAM". This is yaVDRs default shutdown method. What it does is shutting down running programs like the VDR itself and putting the PC into the so called "S3" powerstate. In this state only the PCs RAM remains powered. Everthing else like the CPU, the harddrive or the fans are powered down. While consuming only very little energy in this state this method let's you start your PC within a few seconds. The benefit of yaVDR 0.3s new "s2ram" method is that works on even more hardware configurations than the method used in earlier versions of yaVDR. If your PC didn't support S3 very well with yaVDR 0.2 or older: Give it a new try with yaVDR 0.3. We're pretty sure all of the old problems are simply gone for good! Please keep in mind that "uswsusp" also depends on your PCs mainboard to support S3. If your PC is rather old or S3 is disabled in the BIOS it won't work.

The second method makes use of the "s2disk" component. If you choose "suspend to DISK" as the shutdown method in yaVDRs webfrontend your computer will use the so called "S4" state to power down. This state is also known as "hibernation". In this state nearly the same amount of energy is consumed as if you shut down your PC "normally". The process of powering down takes a little bit longer, but you get a big feature in return for that: USB wakeup works with "suspend to DISK" also! If you've ever used hibernation in Linux before you'll now that there is a little bit of a downside: Waking up can take very long. Given the tremendously fast boot speed of yaVDR 0.3 we decided to perform a normal boot instead. That's why we sometimes call it "fake S4". In short: if you prefer a powered off PC over S3 but want to start it using your USB remote, give "suspend to DISK" a try. You'll get the best of both worlds. Please be aware that "s2disk" depends on a swap partition to be present. If you decided not to use one during installation it wont work out of the box.

What if you want to use the old "kernel" method instead? Well, it's not completely gone. Simply rename the s2ram binary like this "mv /usr/sbin/s2ram /usr/sbin/s2ram.disable" and save your shutdown method again in yaVDRs webfrontend. But we're quite sure that there's no need to go back to the old method as "Userspace Software Suspend" is just a great piece of software!