TIP_Gentoo_Install_and_Migrate

If your installing Gentoo on old/slow hardware it can sometime be kinda painful if your in a hurry. Following these steps you can setup a new system using your 12 core server at work/school... and then migrate your install over to your old Pentium 75 or your Commodore 64, after everything is done emerging using the faster computer from work/school.

(feel free to pitch in and expand/improve/clean up this article this is just my 10 minute overview of what I went through over the last day or so, hopefully someone finds it useful)

Initial Install

Both the fast/slow machines need some prep work done to them before we can migrate the install. I suggest doing the steps on fast hardware first and then while things are emerging and/or downloading come back and run through the initial install prep work for the slow system so its ready to go.

(Fast Hardware)

• Log into your faster/better system either running linux as its OS, or boot off of a live CD.
• First thing you will want to do is make a dir to setup/install your new gentoo system. To make things consistant with the install guides lets use /mnt/gentoo/.

# mkdir /mnt/gentoo

• Next we want to jump straight to the Installing the Gentoo Installation Files (gentoo install guide step 5). (skip the initial fdisk, mkfs, mount commands, we want to jump to download and untar'ing of the stage3/portage files)
• Then mount proc/dev as instructed in the install guide
• chroot and run your install as usual...
• Gentoo install guide - step 7 - Configuring the Kernel: This step can be preformed at this time on the faster hardware, just keep in mind that any hardware research/probing (lspci, lsusb, lshw, cat /proc/cpuinfo, etc) needs to be done on the slower machine because thats where this kernel actually needs to run.
• Gentoo installl guide - step 10 - Configuring the Bootloader: This entire step can be preformed on the fast system other than actually writing to the MBR. WARNING if you run grub-install or manually rewrite your boot records using grub/lilo you will toast your current systems ability to boot so be careful or just do this whole step of the guide once you've migrated.
• (Optional but recommended) At this point I suggest installing any/all additional software before you migrate over to your slower hardware as its going to be faster to install/compile software now before you migrate than after.
• At this point you can exit the chroot and you are ready to migrate your install to the older hardware
• Ready to migrate

(Slow Hardware)

Now on the old hardware we need to do all the staging/prep work that you would usually do before a gentoo install. (aka the fdisk, mkfs, mount'ing that we skipped above)

• Boot a Gentoo install CD (minimal works fine/preferred)
• fdisk /dev/sdX
• mkfs.ext2 /dev/sdX1
• mkswap /dev/sdX2
• mkfs.reiserfs /dev/sdX3
• mkdir -p /mnt/gentoo
• swapon /dev/sdX2
• mount /dev/sdX3 /mnt/gentoo
• mkdir /mnt/gentoo/boot
• mount /dev/sdX1 /mnt/gentoo/boot
• Ready to migrate

Migration From the Fast Hardware to the Slow Hardware

Once both the fast and slow systems are ready to migrate you have 2 options.

With network connectivity

tar cfv - /chroot/folder/on/good/hardware/* | ssh HOSTorIP "(cd /mnt/gentoo/; tar xf -)"

With out

(would someone who knows tar better than me put the tar/untar steps in here to where they could do roughly the following)

• (fast system)
  • create tar
  • copy to USB drive/cdrom
  • eject media
• (slow system)
  • mount media
  • untar file into /mnt/gentoo
  • eject media

Post Migration Install Steps (slow system)

• mount -t proc none /mnt/gentoo/proc
• mount -o bind /dev /mnt/gentoo/dev
• chroot /mnt/gentoo /bin/bash
• env-update
• source /etc/profile
• export PS1="(chroot) $PS1"
• run grub-install per the Gentoo install guide
• exit chroot
• umount /mnt/gentoo/dev /mnt/gentoo/proc /mnt/gentoo/boot /mnt/gentoo
• reboot
• done

References

• Using tar to copy directories with hard links via ssh