Preloading [WAS: Re: SuSE Project SUPER]

[chasd]

Linus Walleij wrote:

> Agreed, what "other" OS:es (Vista, MacOS X) do is to come pre- 
> installed,
> i.e. it was booted once by a technician out of sight of the user. Then
> they leverage on that.

OS X is pre-installed, but not boot-optimized. The OS is a standard  
image like most other pre-installed OS's. The first boot by the end  
user creates an ordered, compressed archive of the specific kernel  
modules for the exact hardware available. Sort of like an initrd ;)  
However, after the configuration the system doesn't reboot, you are  
presented with the configured system running. The user gets all the  
shiny without suffering a first boot first.

One thing OS X attempts to do is for any file ( system _or_ user ) <  
20 MB,  it consolidates all the blocks for that file on disk to  
decrease seeks. It does this in the background when the system is  
idle. This speeds up booting, opening apps, and loading ( most )  
files into apps.

Vista in my experience is pre-installed but not optimized either. It  
goes through a lengthy "determining the performance of your system" -  
I guess to decide what kind of interface to display.  It too switches  
to a running system without a reboot ( unlike XP ) so again the end  
user does not experience a cold boot to wait through to use the  
system. There is much thrashing of the disk for the first few days of  
Vista use as it tries to figure out how to optimize for what the end  
user is doing.

Installs of either from optical media is a different experience, and  
more like installing Linux with a reboot at the end. However most  
users never experience that.

Both OS X and Vista have data file search indexing that causes slow  
behavior until the user's files are indexed. That particular slow- 
down was not included by default in Fedora a release or two ago.

The best-guess optimization for an end user won't be the best  
optimization for the _first_ use. What a user does in the first few  
days of use is generally much different from what the user does after  
the system is configured and the user establishes a routine.

To me that means optimizing for a reviewer is orthogonal if not 180  
degrees from the the best optimization for a "normal" end user,  
whatever that is determined to be.

I personally dislike waiting for preloading, because I don't do the  
same thing in the same order every day. But I know I'm weird.


Charles Dostale