4 ms·

Haha yes, this is the default install procedure for Gentoo! :D

by shocks 10y ago

hashhar 10y ago
Arch also does it. The first time I encountered this was when I accidentally deleted my EFI partition and was unable to boot. Boot into live media, chroot, run grub-install and rejoice.
- Accacin 10y ago
  Yeah as an Arch user I've used it a few times where an pacman -Syu has caused something to break and it's pretty easy to chroot into your system and fix the broken package.
exDM69 10y ago
Something like this has been my default way of installing Linux for years - and I've installed Debian, Ubuntu (with debootstrap), Gentoo and Arch this way. Typically I just create another partition to my LVM volume group, chroot and install over there and then reboot without removing the old OS install and I run the install procedure from the old OS (instead of booting from a Live CD / usb stick). I do this because I know it works and there's no guesswork involved in what the OS installer does. They aren't really intended for installing beside another system and the default partitioning options aren't always that great (RAID, LVM, crypto, etc). Basically you only need 3 things to run Linux: kernel, initramfs and rootfs.
- yellowapple 10y ago
  You really only need two (kernel and initrd/initramfs), at least to get into a basic running state. This requires building your own initrd, of course, but it's pretty common in non-graphical Linux installers (Slackware's install media still does this, IIRC). I think it's even possible to embed the initrd in the kernel binary itself, but I've never really investigated that.
  - LookASquirrel 10y ago
    You can ditch the initrd if you compile in the kernel the drivers you need to boot the system, as a minimal example SATA/SCSI, EXT4/JFS, that usually are compiled as kernel modules.
    - digi_owl 10y ago
      How most sane distros do it. Build a kernel with the most common hardware built into it, and use that to bootstrap. No need for messy things like balled up temporary rootfs in a ram drive. Initrd/initramfs have become an excuse for piling on complexities that frankly should be added by the sysadmin after initial install.
      - exDM69 10y ago
        The purpose of the initrd to have the initrd bootstrap to rootfs. This involves userspace tools like mdadm, lvm2, cryptsetup, zfsprogs, etc. It's not very common to need kernel modules (drivers) on initrd on typical hardware.
        yellowapple 10y ago
        It's not common to need them, perhaps, but it's still useful if you don't want to recompile your kernel just to add on-boot support for various devices. Slackware's 'mkinitrd' tool is one example of this sort of approach; you can add various modules (like for your root filesystem, keyboard, etc.) by adding to the $MODULE_LIST variable defined in '/etc/mkinitrd.conf' or by running 'mkinitrd -k $MODULES'. You can of course accomplish similar things by just recompiling the kernel (which Slackware makes very easy to do), but if you still need to use 'mkinitrd' anyway (perhaps because you're using LVM or softraid or LUKS), it's often more convenient to just throw in the modules you need while you're at it.
        sh_tinh_hair 10y ago
        The keywords there are 'typical hardware', but it can get worse. How about 'badly selected' hardware on a short time frame, in situ, waiting for an install and application port process to be performed by non-technical users following a recipe. Proprietary drivers for network and soft raid with a large enterprise linux vendor support and site license basically voided. There are worse things than starting an install,loading storage drivers, creating the lvm partitioning, hup'ing disk druid, installing, rebooting and adding the network driver to initrd, and having to explain and document that manual procedure to the same people who ordered the hardware...but I've forgotten them.
- josteink 10y ago
  > Basically you only need 3 things to run Linux: kernel, initramfs and rootfs. And networking, fully functional networking. If you've missed out the FW packages for your wifi drivers, you will have a hard time using your package manager to get those missing bits ;) Probably not an issue for servers, but for those who'd like to do "complex" desktop/laptop install with ZFS/btrfs roots or whatever, it's an easy mistake to make.
toxik 10y ago
It's funny, I knew how to do that when I borked my systems back in 2004 only because the Gentoo installation instructions were like that.
- HeadlessChild 10y ago
  Sort of the same for me but I learnt it from the Arch Linux installation process.

Haha yes, this is the default install procedure for Gentoo! :D

by shocks 10y ago

Haha yes, this is the default install procedure for Gentoo! :D

Arch also does it. The first time I encountered this was when I accidentally deleted my EFI partition and was unable to boot. Boot into live media, chroot, run grub-install and rejoice.

Accacin 10y ago
Yeah as an Arch user I've used it a few times where an pacman -Syu has caused something to break and it's pretty easy to chroot into your system and fix the broken package.

exDM69 10y ago

Something like this has been my default way of installing Linux for years - and I've installed Debian, Ubuntu (with debootstrap), Gentoo and Arch this way. Typically I just create another partition to my LVM volume group, chroot and install over there and then reboot without removing the old OS install and I run the install procedure from the old OS (instead of booting from a Live CD / usb stick). I do this because I know it works and there's no guesswork involved in what the OS installer does. They aren't really intended for installing beside another system and the default partitioning options aren't always that great (RAID, LVM, crypto, etc). Basically you only need 3 things to run Linux: kernel, initramfs and rootfs.

yellowapple 10y ago
You really only need two (kernel and initrd/initramfs), at least to get into a basic running state. This requires building your own initrd, of course, but it's pretty common in non-graphical Linux installers (Slackware's install media still does this, IIRC). I think it's even possible to embed the initrd in the kernel binary itself, but I've never really investigated that.
- LookASquirrel 10y ago
  You can ditch the initrd if you compile in the kernel the drivers you need to boot the system, as a minimal example SATA/SCSI, EXT4/JFS, that usually are compiled as kernel modules.
  - digi_owl 10y ago
    How most sane distros do it. Build a kernel with the most common hardware built into it, and use that to bootstrap. No need for messy things like balled up temporary rootfs in a ram drive. Initrd/initramfs have become an excuse for piling on complexities that frankly should be added by the sysadmin after initial install.
    - exDM69 10y ago
      The purpose of the initrd to have the initrd bootstrap to rootfs. This involves userspace tools like mdadm, lvm2, cryptsetup, zfsprogs, etc. It's not very common to need kernel modules (drivers) on initrd on typical hardware.
      - yellowapple 10y ago
        It's not common to need them, perhaps, but it's still useful if you don't want to recompile your kernel just to add on-boot support for various devices. Slackware's 'mkinitrd' tool is one example of this sort of approach; you can add various modules (like for your root filesystem, keyboard, etc.) by adding to the $MODULE_LIST variable defined in '/etc/mkinitrd.conf' or by running 'mkinitrd -k $MODULES'. You can of course accomplish similar things by just recompiling the kernel (which Slackware makes very easy to do), but if you still need to use 'mkinitrd' anyway (perhaps because you're using LVM or softraid or LUKS), it's often more convenient to just throw in the modules you need while you're at it.
      - sh_tinh_hair 10y ago
        The keywords there are 'typical hardware', but it can get worse. How about 'badly selected' hardware on a short time frame, in situ, waiting for an install and application port process to be performed by non-technical users following a recipe. Proprietary drivers for network and soft raid with a large enterprise linux vendor support and site license basically voided. There are worse things than starting an install,loading storage drivers, creating the lvm partitioning, hup'ing disk druid, installing, rebooting and adding the network driver to initrd, and having to explain and document that manual procedure to the same people who ordered the hardware...but I've forgotten them.
josteink 10y ago
> Basically you only need 3 things to run Linux: kernel, initramfs and rootfs. And networking, fully functional networking. If you've missed out the FW packages for your wifi drivers, you will have a hard time using your package manager to get those missing bits ;) Probably not an issue for servers, but for those who'd like to do "complex" desktop/laptop install with ZFS/btrfs roots or whatever, it's an easy mistake to make.

toxik 10y ago

It's funny, I knew how to do that when I borked my systems back in 2004 only because the Gentoo installation instructions were like that.

HeadlessChild 10y ago
Sort of the same for me but I learnt it from the Arch Linux installation process.