[mythtv-users] Software suspend (swsusp2)

[Henk Poley]

I thought I'd share my experience with using swsusp2 (can be found at 
http://swsusp.sf.net/ ). Installing swsusp2 is fairly straightforward when 
you are familiar with kernel compilation, you will probably need vanilla 
kernel sources for the patches to work. Everything is pretty good explained 
on the website. btw, enable LZF compression, but do not enable gzip, it will 
slow down the suspension process remarkably, it is only needed if you have a 
small swapspace.

When you suspend the machine it brings down the network connections (eth0, and 
maybe others), deamons depending on the net will be brought down by the 
init / rc system. So don't forget to add mythbackend and other deamons you 
need (sshd?) in the configuration file ( /etc/suspend.conf ). The startup of 
the deamons after suspension doesn't work on Gentoo, on that distro you can 
start the command "rc default" from the hiberbnate script to bring back the 
system in the default runlevel and thus start all stopped deamons in 
necessairy.

The stupidity with the MythTV 0.14's powersave feature is that you need to 
stop MythFrontend before the backend will call the 'halting' scripts. So you 
basicly can't build a system that will only show the frontend at all time, 
while also shutting down the machine. Ah well, whouldn't mown, OSS, patch it, 
etc.

As a rather ugly hack I made a little looping script like this:

---
#!/bin/bash

while [ 1 ]
do
  mythfrontend
  Xdialog --msgbox "Press PLAY to start the frontend (again)" 12 50
done
---

And told the other users that they should exit the frontend when not in use 
("uh? why doesn't it go into standby automaticaly?"). When you now "killall 
xdialog" from the hibernate script, the loop will restart mythfrontend. You 
could probably make it more clean by saving the Xdialog PID somewhere and 
killing only that PID.

I couldn't get swsusp2 to resume correctly on another machine, while using the 
nVidia binary drivers and keeping X running, though YMMV. Other people are 
using swsusp2 with nVidia cards. Yes, tried all the documented tricks.

Suspension was canceled on my MythTV system a couple of times when I tried. So 
I am currently not using it. I was told it was probably fixed with a recent 
patchset. But when it works for you it will save you a couple of valuable 
seconds ;-) to boot the system, not to mention having the file caches already 
filled and loaded.

	Henk Poley <><