New hardware, old Linuxes

I swapped out my 5 years old machine to a bit more contemporary one.
Everything except video card (gtx 560) and one irrelevant hdd got swapped out.
Relevant changes were - ahci/ehci mode for hdd-s, new sound chip, new network chip.

Practical philosophy for hardwaring:
Decide what you really need - for example, in my case:
- inverted-layout box, as I keep it against wall and wanted to turn back panel to front (which would have caused blocked cooling for classic box). AND - it's very, very inconvinient to have big video card and hdd-s kissing each other.
- bigger hdd bay, for not cramming several hdd-s on top of each other.
- modular psu, as miditowers are bloody tight really.
- and if you do not need raid or full-ATX or simply-mucho-expencive MB, then really, you don't.
Why back panel in front, you ask? Because it irritates me to have usb-s divided between ends of box. So I cannibalized the front and planted usb-s, switches and leds to back panel, closed holes in front panel and - done.
- There are two things one have to read - as RTFM - MB manual and Bios. Don't skip!

Software, fixing it:
I packed (and backed) up all my current 5 linuxes with fsarchiver. Then I connected the new system-hdd to the old machine and unpacked distros to their new partitions.
When the new box was ready - bios checked etc, it got it's hdd-s installed. First boot was from usb stick (which happened to be PartedMagic).
Usb because, with such a total overhaul there are some things to be done before you can have any hope to see your dear display manager again.

# Did the distros end up on different partitions (of originals)? Open up all etc/fstab-s and correct them. There is no such problem if fstab uses UUIDs (sudo blkid to get whole list) as fsarchiver restores systems with original UUID.

# Chroot.
For that procedure it's better to google and find your own recipe - I am not sure that mine is the very right one.
What you have to do is, basically: mount and bind targets' /sys, /proc and /dev (for debian, better to mount also sysfs) to /mnt, then
sudo chroot /mnt. And fun begins.
Patients: Slackware, Salix, Vsido and my own netinstalled Wheezy and Sid. All need new initrd files (changed drivers!)
- Slackware and Salix have most nice mkinitrd script, currently ran like that:
/usr/share/mkinitrd/mkinitrd_command_generator.sh -k 3.10.17
which works no problems. Run lilo afterwards. In my case, lilo is in root part (not MBR), and has to be run with partition-number: lilo -b /dev/sda2 -c
- Debians: dpkg-reconfigure linux-image-3.x.x... (number is uname -r). Which is dandy, except that uname -r in chroot shows number for host kernel. So I checked up how old initrds look and - seems that everything between kernels' number-start and .gz IS the right thing. Example:
dpkg-reconfigure linux-image-3.11-10.dmz.1-liquorix-amd64
The good thing with previous command is - it also renews your grub.
Done with chroot. 'exit' and 'umount' everything you mounted.

- And that was all that Slackware needed for reaching the desktop.
- Not so with Debians - error: no screens, and no xorg. To cut it short, the solution was  simple: delete /etc/X11/xorg.conf and recreate it. Mind! I am talking of Nvidia binary driver. It installs itself and also makes new xorg.conf. I do not know what happens with other video drivers.

# Network: new chip, new interface = no network.
The important file is
/etc/udev/rules.d/70-persistent-net.rules
Only Wheezy - somehow - managed to create new entry there (with new mac number!), and named it as eth1. And/but - eth1 does not start automatically - still no network.
So, I copied this new entry to every other distro, changed NAME="eth0", and that was that. I still do not know where to find mac numbers :)
It is also said that deleting that file and rebooting creates automagically the new (correct) one.

# alsa gave a looooong list of warnings when starting (but worked). In Slackware, delete
/var/lib/alsa/asound.state
and create new, 'alsactl store', done.
In Debians.... I think it just went away after first boot.

# Sid and sensors. Or, really - no sensors... Run:
sudo sensors-detect, answer questions, let it write modules and run:
sudo /etc/init.d/kmod start
Done.

# Annoyances:
- monitor dimensions changed and some (desktopy) things were not in right places anymore.
- sensors data presentation errors in conky (new cpu, new 'cut's  etc)
- console resos out of whack. None that is possible according to vbeinfo is fitting for 1920x1080. and KMS doesn't work as I use proprietary driver... bugger. Still no solution here.
- some 5-6 irritable hours thrown into googling.
And I am sure there will be more things creeping out.

But all in all - it was quite alright compared to coming reinstall of borked Windows. Always hated that...
'Old Linux in new box' can be summed like that: fstab, initrd, 70-persistent-net.rules. Done.