Boot

Turning off Resume from Hibernation in Ubuntu 10.04

2010-10-03

I use dm-crypt on all my machines now, including laptops, to provide full-disk encryption. I also use it to encrypt swap partitions with a randomly-generated key. All of these are features that Ubuntu 10.04 provides out-of-the-box, at least when you use the alternate CD to install.

I also recently installed µswsusp on one of my laptops, a userspace hibernation facility. I didn’t really connect the dots until one day I left the laptop running, coming back to find it hibernated. When I tried to resume, the boot process hung as the kernel complained it couldn’t resume the image. After a facepalm moment (of course this wouldn’t work - the encryption key isn’t constant across boots -  you have to use a constant key if you want to get hibernation working), I eventually figured out how to book the machine: use the noresume parameter when booting the kernel.

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