# Laptop system migration. How to do it as smooth as possible?

## urcindalo

Hi everyone.

My old laptop died (Packard Bell EasyNote TJ62, the worst piece of hardware I've ever had) and I have just ordered a new Asus X45HR-SX196V for a very good price. I will get it next Tuesday, October the 30th.

I intend to copy over my old Gentoo installlation from the old HD to the new one. Apart from the obvious kernel reconfiguration through chroot, I'd like to experience the smoother migration possible. So, I have a few questions for the geek in you:   :Smile: 

a) Which processor type and features must I select in both the kernel and /etc/make.conf?

     * New CPU: Intel Core i3-2350M

b) After a reboot into the new kernel with suitable drivers and modules for the new hardware, will the copied over portage @world work? I guess so since both CPUs are amd64 and I'm upgrading, but I ask just in case (old CPU:AMD Athlon Dual-Core QL-65).

c) Both laptops, old and new, include a dedicated ATI graphics card. Since I used the ati xorg driver in the old one, I guess I won't have any issues booting into a graphical display with the new laptop for the first time, will I?

d) Anything else I didn't mention I should think of or take care of?

My intention is to recover my working box as soon as possible. Later on, and patiently, I will re-emerge @world with the new settings in make.conf.

Thanks in advance.

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## The Doctor

If you set -mach=native or similar for the AMD Athlon Dual-Core, you can't use the binaries on the Intel i3.

I would stick with CFLAGS="-march=native  -O2 -pipe" as they are fairly safe settings, and march=native is the optimum cpu setting.

Unless you intend to rebuild your entire system on your old laptop first, I don't think you can do that. The best you can hope for is coping your config files and data.

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## Jaglover

There is a good chance the base system will work, but you need to do emerge -e world to rebuild your apps.

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## urcindalo

Thanks for your help.

 *The Doctor wrote:*   

> If you set -mach=native or similar for the AMD Athlon Dual-Core, you can't use the binaries on the Intel i3.

 

I had -march=amd64. So, good chances the generated binaries will work on the Intel i3? I just ask. I think so but I'd like a more educated guess from someone savvier than me.

 *The Doctor wrote:*   

> I would stick with CFLAGS="-march=native  -O2 -pipe" as they are fairly safe settings, and march=native is the optimum cpu setting.

 

-O2 -pipe were exactly my CFLAGS. I don't like to mess around with them. Thanks for the -march=native tip.

 *The Doctor wrote:*   

> Unless you intend to rebuild your entire system on your old laptop first, I don't think you can do that. The best you can hope for is coping your config files and data.

 

No, my old laptop died. What I want to do is to take the Gentoo installation from my old laptop's HD and copy it over in the new one's HD, with the minimal fuss.

 *Jaglover wrote:*   

> There is a good chance the base system will work, but you need to do emerge -e world to rebuild your apps.

 

That's what I intend to do, but first I want to get a booting and working system as soon as possible.

I'm also really interested in knowing if I missed or overlooked something in the initial message as the steps to take care of.

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## Veldrin

there is no such thing a -march=amd64. Check your -march= again (once you have it on the new machine)

The main problem is, that code optimized for an amd cpu use 3dnow instruction, which are not supported by intel cpus. luckily those instructions are only (mostly) used by multimedia/graphical application. 

So what Jaglover meant to explain, is that you could your system up and running to some part (read CLI), but do not expect everything to work. 

And instead of having to figure out which package actually needs rebuilding, and which does not, just run emerge -e world to rebuild everything. Yes, it is slightly an overkill, but is still faster than rebuilding the box from scratch. 

HTH

V.

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## urcindalo

 *Veldrin wrote:*   

> there is no such thing a -march=amd64. Check your -march= again (once you have it on the new machine)

 

Oops! Could it be athlon, then? I think it started with an "a". I set it 4 years ago and didn't changed it since then  :Confused: 

 *Veldrin wrote:*   

> The main problem is, that code optimized for an amd cpu use 3dnow instruction, which are not supported by intel cpus. luckily those instructions are only (mostly) used by multimedia/graphical application.

 

Good point. Thank you. I think I got 3dnow among the USE flags.

However, I'm more confused now. Thanks to you I just discovered I also have the 3dnow USE flag selected for my work desktop box on purpose (Intel Core2 Quad CPU Q8300) which has no 3dnow option among its capabilities as stated by lshw, but until now I haven't experienced any failures.

I had them the past with the laptop, though, when I accidentally chose sse3 in it and the OpenCV package couldn't help crashing until I noticed the mistake and removed the offending USE flag. Why isn't the same thing happening on my desktop Intel work box with 3dnow? Even kdelibs is built with it, and I'm a KDE guy.

 *Veldrin wrote:*   

> So what Jaglover meant to explain, is that you could your system up and running to some part (read CLI), but do not expect everything to work. 
> 
> And instead of having to figure out which package actually needs rebuilding, and which does not, just run emerge -e world to rebuild everything. Yes, it is slightly an overkill, but is still faster than rebuilding the box from scratch. 
> 
> HTH
> ...

 

Point taken. As long as I can boot into a working CLI I'll be a happy camper. I don't mind leaving the new laptop heating my living room for as long as needed  :Very Happy: 

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