Friday, January 28, 2011

Install Linux over ssh

I'm a totally blind individual so can't install Linux with the normal install process. SSH does work for me how ever, is it possible to use an ssh connection to remotely install a Linux server? Ideally I'd like to pop in a cd, power on the machine I want to install Linux on, SSH into it and install through SSH. I'm not perticular about what distro I use, I also have experience with FreeBSD and OpenBSD if it's possible to do this with them.

  • I don't know about SSH, but it's possible to configure your system to use a serial console, by using console=ttyS0 (for the first serial port) or console=ttyUSB0 (for a USB-connected serial port) on the kernel command line.

    By default this uses 9600, no parity, 8 bit, no flow control. You can specify a different baud rate if you want: console=ttyS0,115200

    Tom Ritter : I'm guessing he needs SSH because it works with some sort of screen-reading software, possibly on Windows.
    Chris Jester-Young : I'm hoping that there is screen-reading software that works on COM ports too.
    Jared : I think there is but I don't have the cables or USB adaptors necessary.
  • Yes. I've done it with gentoo. However, you may need help turning on ssh after the livecd boots. So the steps would look like:

    1. Pop in the CD, power on the computer
    2. Let it load
    3. Turn on SSHD - I'm not sure if it does this automatically or not, can't remember
    4. SSH into it
    5. Do all the install steps, taking very special care with the networking configuration
    6. Reboot, and cross your toes
    7. SSH into the newly installed computer and finish configuration/installation
    Jared : If I remember correctly gentoo compiles a bunch of stuff. I was planning on doing the install in a virtual machine what are the specs it will need?
    Tom Ritter : gentoo is indeed completely compiled. I think its motto is "Use the Source, Luke". The specs are low. I mean if the CPU is over 500MHz, you have more than 256MB of RAM, and 2GB free you'll be fine. And that's just what I did the other month. They're probably lower.
    Gert M : For Gentoo type these after the cd loads: (the ssh server doesn't auto start) $ /etc/init.d/sshd start $ passwd and enter the password for root $ ifconfig to check your IP and you're set. (assuming you have network up and running)
    From Tom Ritter
  • One thing you could do is find a livecd or liveusb that boots and starts the network and ssh automatically. Something like a customized version of SystemRescueCd may work.

    Once you have a system booted, and you can SSH in and then use something like debootstrap to perform the install of a debian or ubuntu system.

    From Zoredache
  • This is not answering the exact question that you asked but it's possible that it resolves the problem that you want to deal with.

    If your concern is that you can't use a normal install process, you might be best off with an unattended install. If you're using virtual machines this might be very quick to test.

    In the redhat based world, such as CentOS, Fedora and others, kickstart is available. Effectively, you create a file that answers all the questions that the installer would ask and it installs itself. All you need to do is point the kernel at the kickstart file which could be on the install CD if you're willing to make a new image for each machine, but more usefully would be on a webserver somewhere so at the boot prompt you can do:

    linux ks=http://somehost.tld/path/to/my/kickstart.cfg

    The next stage of automation is getting that going automatically and for that you need to PXE boot. The short version of what happens there is that the BIOS loads some code that asks your dhcp server for its networking information and also for a network location (host and filename) that defines what should happen next. Then it loads whatever it would normally get from grub (ie kernel/initrd + kernel parameters, including the location of the kickstart file) via TFTP from that location as specified by the dhcp server.

    PXE boot initiated automated installation is available in non-RedHat clones as well, although I don't know the details.

    The best news is that this fairly involved setup is automated and documented for you in a big way by the fine folks of the cobbler project. I was able to get from never having seen cobbler to a fully functional automated installation environment in a morning.

    Jared : Do you have any URL's to kickstart files I can use as a refference? I've found information on writing them but nothing I can use as a starting point.
    dotplus : Among other places, the cobbler project will give you a default. The easiest way to get one that you like is probably to look in /root/anaconda-ks.cfg of an existing RHEL/CentOS system. The installer, anaconda, creates a kickstart config file that will enable you to repeat the installation process. Failing that, here is one that I used recently to setup a centos5.3 virtual machine with all package groups turned off but "base": http://www.allgoodbits.com/files/
    From dotplus
  • If you are planning to use a virtualized OS I would just download a preconfigured Ubuntu version 8.04 Long Term Support JeOS (It stands for Just Enough Operating System, it comes configured with special vmware guest modules. LTS means less fiddling with marginal upgrades). If your primary interest is server, that is enough -- otherwise the package manager will download and install a desktop environment if you install any package that depends on one. You can get a good free image here: http://www.vmware.com/appliances/directory/1282 link text. You can ssh in right away with the default password (in this case user = 'User', password = 'user'. I believe root is disabled by default so use sudo to change passwords etc.) This works great on VMware player, which defaults to bridged networking so you can just ssh in over the lan, or forward ports and have access from anywhere. You will start out with a system similar to a Debian 'base system' netinstall. Of course, if you are using this for a crucial system you would want to somehow audit or verify the reliability of the original image, not something I am an expert on.

    From bvmou

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