Preloading [WAS: Re: SuSE Project SUPER]

[Douglas McClendon]

Linus Walleij wrote:
> On Sun, 13 Jan 2008, Jeff Spaleta wrote:
> 
>> That wont help the critical first impression phase..
>  
> 
> They are of course doing much more agressive things than simple 
> preloading, more like suspend-to-disk, so the user actually more or less 
> resumes a pre-booted image customized for that machine at "boot" time.
> 
> I wonder if we could do that.

I've considered this in the past, specifically for my mythtv home 
theatre box.

The theory is that the 120G disk is a big data disk and has nothing to 
do with the OS.  The OS can live on a little usbflash.

Then, once thinking about it that way, and remembering the "repeatable 
resume" feature from vmware, the following idea occurred to me-

Do just as you say- Do a livecd/liveusb style copy-on-write boot, where 
the rootfs is read-only and changes go to a devicemapper snapshot.  Then 
do a hibernate during install, but save a copy of this golden hibernate 
(swap) image along with a golden copy of the dm-snapshot.  Also, make 
the hibernate do an unmount of all data disks, and a resume do a 
remounting of them.

Then, every power up of the system, would be a resume from the golden 
hibernation image.  With a post-resume script that mounts data disks, 
resets the clock, and does whatever else is needed.

Really it is similar behavior as a vmware 'repeatable resume', but 
non-virtual.

-dmc