Clowns In My Coffee

I’ve been cavalier with the power saving settings on the desktop computers I interact with on regular basis. Throw in the fact that I recently swapped in a dual-core Athlon 64 that chews through 13o watts (eh, what can I say? The mainboard is socket 939) when it’s under load, and the idea of leaving my computer on starts making me itch a bit.

Since I also started using a laptop in earnest not so long ago, I notice how well recent models do with turning themselves off when you close the lid, and being available for serious work soon after you open it. The magic is attained through “suspend-to-ram” or, as it’s known in ACPI-speak, “S3″ standby — the only system component that gets power in this state is the system’s RAM. Via slashdot (yes, it still has its uses!), I came across a detailed article on enabling S3 mode in Windows XP; now, I can do Start->Turn Off Computer->Stand By and all the fans power down, and the computer sucks up just enough juice to keep the contents of RAM around. Nice. The article even shows you how to enable wake-on-lan so you can have your cake and eat most of it too (although it seems like any traffic to your network card is going to wake your machine up, so maybe it’s not all that valuable). Another pointer I lifted from the /. thread is that you can see which ACPI modes are available with powercfg -a from the command line.

OK, but what about an operating system I’d actually want to use as a file server? There’s distressingly little of a distribution-neutral bent out there, although Matthew Garrett has a nice view from three centimetres, including the following:

In a lot of cases, it’s just down to bugs in the drivers. Restoring hardware state can be hard, especially if you don’t actually have all the documentation for the hardware to start with - traditionally, many Linux drivers have ended up depending on the BIOS to have programmed the hardware into a semi-sane state, and there’s no guarantee that that will happen with ACPI.

Hmm, doesn’t sound encouraging, does it?  Well, with the possibilities swirling in my head, of course I had to try standby on Feisty Fawn, which, as I could have expected from reading the above, worked on the “going to sleep” part but not on the “waking back up” step. Furthermore, the very attempt seems to have angered a patron deity or deities of the long-forgotten and presumed overwritten Solaris 10 bootloader (or so the results of a search on “bad PBR sig” would seem to indicate?), and even reinstalling GRUB did not appease the offended deity or deities. Well, that’s what rescue CDs are for, right?

Next: let’s see what this button does!