Category: Linux

What would you like to see most in minix?

JSEvansLeave a comment

I’m working on a couple of presentations and I wanted to share this nugget of joy with anyone who hasn’t actually read it.

Path: gmdzi!unido!fauern!ira.uka.de!sol.ctr.columbia.edu!zaphod.mps.
ohio-state.edu!wupost!uunet!mcsun!news.funet.fi!hydra!klaava!torvalds
From: torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds)
Newsgroups: comp.os.minix
Subject: What would you like to see most in minix?
Summary: small poll for my new operating system
Keywords: 386, preferences
Message-ID: <1991Aug25.205708.9541@klaava.Helsinki.FI>
Date: 25 Aug 91 20:57:08 GMT
Organization: University of Helsinki
Lines: 20

Hello everybody out there using minix -

I'm doing a (free) operating system (just a hobby, won't be big and
professional like gnu) for 386(486) AT clones.  This has been brewing
since april, and is starting to get ready.  I'd like any feedback on
things people like/dislike in minix, as my OS resembles it somewhat
(same physical layout of the file-system (due to practical reasons)
among other things).

I've currently ported bash(1.08) and gcc(1.40), and things seem to work.
This implies that I'll get something practical within a few months, and
I'd like to know what features most people would want.  Any suggestions
are welcome, but I won't promise I'll implement them :-)

Linus (torvalds@kruuna.helsinki.fi)

PS.  Yes - it's free of any minix code, and it has a multi-threaded fs.
It is NOT protable (uses 386 task switching etc), and it probably never
will support anything other than AT-harddisks, as that's all I have :-(.
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Linux newbies shouldn’t dual boot

JSEvansLeave a comment

If you lurk around many Linux support forums, you are bound to see the regular post that looks something like this:

Hi, I’m new to Linux. I tried to dual boot Windows and Ubuntu, now I can’t use my computer at all because it has errors. Help!!!

Troubleshooting Grub errors is difficult enough. Troubleshooting Grub errors when you know very little about how any of it works or when getting help from strangers on the internet is even more difficult to nearly impossible.

I offer 3 suggestions for newbs who want to learn Linux other than dual booting.

  1. Use a virtual machine. Download Virtualbox on any platform, and install Linux there. It is a little slower than a real computer, but it is safe. If something breaks, nothing is lost. Just start again.
  2. Use bootable live installations. OpenSUSE, Ubuntu, and others allow you to use their Linux distribution from a USB key without ever installing it. This is faster that a VM and when rebooted, it’s like it was never there.
  3. Get a dedicated Linux machine. I’m not talking about spending a ton of money on something new. A raspberry pi will do nicely. So would an old machine from Craigslist. Something that would be used only for Linux and that’s all.

All of these are safe alternatives. I suggest the first option though because it costs nothing except time and your data will be safe.

Advice for Newbies

JSEvansLeave a comment

I originally wrote this as a reply to a Reddit post but as I saved it, comments were blocked.

2867374530_5feabdfbce_bGive yourself little tasks and projects to do. Think of it as being like model kit building. You start with the easy kits like a plane with just a few pieces and as you get better you pick up new things like painting, sanding, and eventually making bigger better kits.
So, start with small things. For example, write a small program with a for-loop and get to know what all if the commands are really doing. This is your basic kit. Add in some variables. Add in user input, and keep going trying new things. Eventually, challenge yourself by learning how to work with a GUI. Sometimes your program will break. This isn’t a bad thing. It teaches you how to debug. What’s important is to take your time and experiment.
The same goes for aspiring system engineers. Learn how to create a virtual machine and install Linux in it. Then learn how to create a web server and then how to get PHP and MySQL working, etc.
A computer course can teach you how to write good code or what all of the system services do that you need but what’s most important is that you don’t give up and never lose your curiosity.

KDE vs XFCE vs Gnome

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Chris Titus recently vlogged about an article showing that KDE 5.17 is now smaller than XFCE 4.14 in memory usage. The article says that in their tests, XFCE actually uses more RAM than KDE. I was very interested in this, but I couldn’t quite believe it and so I ran my own tests.

First of all, we need to compare apples to apples. I created an OpenSUSE VM using Vagrant with KVM/libvirt. It had 4 cores and 4192MB of RAM. This VM has no graphical interface at all. As soon as I got it up, I took the first “No X” measurement. After patching using zypper dup, I took the second “No X” reading. Every reading in this blog post was using the free -m command. I then shut down the VM and cloned it 3 times so each copy should be completely the same.

I installed the desktop environments into their respective VMs using the following commands:

zypper in -t pattern kde


zypper in -t pattern xfce


zypper in -t pattern gnome

After desktop environment was done, I then installed the lightdm display manager. This wasn’t actually necessary with Gnome because it installs gdm as a dependency.

After that, I started the display manager with:

systemctl set-default graphical && systemctl isolate graphical

Once I logging into the graphical environment, I ran xterm and then free -m for the first reading. I then rebooted each machine, and logged in for the second reading. I then installed and started libreoffice-writer. I created a new spreadsheet. That is the “Libreoffice” reading. Finally, I closed LibreOffice and took the third reading.

The results are a little surprising. The averages speak for themselves. KDE does use more than XFCE but not to a shocking amount. In fact, according to the average, only about 68MB. What’s really surprising is how much more Gnome uses than the either two — nearly 200MB more that KDE!

Finally, I also did a df -kh after installing libreoffice-writer on each. KDE is in fact that disk hog by a wide margin and that’s even comparing it to Gnome + gdm + lightdm.

Desktop Test No RAM (MB) Disk (GB) Version
No X 1 54
No X 2 58
Average 56
   
Gnome 1 471 3.34.2
Gnome 2 501
Gnome 3 508
Gnome Libreoffice 547 1.9
Average 507
   
KDE 1 327 5.17.4
KDE 2 284
KDE 3 291
KDE Libreoffice 330 2.3
Average 308
   
XFCE 1 216 4.14
XFCE 2 230
XFCE 3 241
XFCE Libreoffice 272 1.8
Average 240

Creating the Ultimate Container Playground: Salt in LXD

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Introduction: Installing Saltstack

The great thing about being able to spin up several new system containers running multiple Linux distros is that you get to experiment with software like Saltstack without the hassle of creating multiple VM’s. This can be especially daunting on a machine that is lacking resources.

The following directions are how I installed Salt on multiple containers running at the same time but using less that 2G of RAM total for testing. Saltstack easily controlled all of their very different package manager and system configurations effortlessly.

Master and Minion on OpenSUSE

zypper in salt-master salt-minion
echo "10.132.120.155" >> /etc/hosts
systemctl enable salt-master
systemctl start salt-master
systemctl enable salt-minion
systemctl start salt-minion

Minion on Fedora

dnf install salt-minion
echo "10.132.120.155" >> /etc/hosts
systemctl enable salt-minion
systemctl start salt-minion

Minion on Ubuntu

apt update
sudo apt install salt-minion
echo "10.132.120.155" >> /etc/hosts
systemctl enable salt-minion
systemctl restart salt-minion

Minion on Arch

pacman -S salt
echo "10.132.120.155" >> /etc/hosts
systemctl enable salt-minion
systemctl start salt-minion

Minion on CentOS

vim /etc/yum.repos.d/saltstack.repo (see https://docs.saltstack.com/en/latest/topics/installation/rhel.html)
echo "10.132.120.155" >> /etc/hosts
yum install salt-minion
systemctl enable salt-minion
systemctl start salt-minion

Set up Salt Master

opensuse:~ # salt-key -A
The following keys are going to be accepted:
Unaccepted Keys:
opensuse
ubuntu.lxd
arch
fedora
centos
Proceed? [n/Y] y
Key for minion opensuse accepted.
Key for minion ubuntu.lxd accepted.
Key for minion arch accepted.
Key for minion fedora accepted.
Key for minion centos accepted.

Testing Saltstack

opensuse:~ # salt '*' grains.get os         
ubuntu.lxd:
    Ubuntu
centos:
    CentOS
arch:
    Arch
fedora:
    Fedora
opensuse:
    SUSE

opensuse:~ # salt '*' grains.get saltversion
fedora:
    2017.7.3
ubuntu.lxd:
    2017.7.4
centos:
    2018.3.0
opensuse:
    2018.3.0
arch:
    2018.3.0

Install a package

opensuse:~ # salt '*' pkg.install mutt
arch:
    ----------
    mailcap:
        ----------
        new:
            2.1.48+14+g5811758-1
        old:
    mutt:
        ----------
        new:
            1.10.0-1
        old:
centos:
    ----------
    mailcap:
        ----------
        new:
            2.1.41-2.el7
        old:
    mutt:
        ----------
        new:
            5:1.5.21-27.el7
        old:
    tokyocabinet:
        ----------
        new:
            1.4.48-3.el7
        old:
    urlview:
        ----------
        new:
            0.9-15.20121210git6cfcad.el7
        old:
fedora:
    ----------
    mailcap:
        ----------
        new:
            2.1.48-2.fc27
        old:
    mutt:
        ----------
        new:
            5:1.9.2-1.fc27
        old:
    perl-Time-Local:
        ----------
        new:
            1:1.250-394.fc27
        old:
    tokyocabinet:
        ----------
        new:
            1.4.48-9.fc27
        old:
    urlview:
        ----------
        new:
            0.9-22.20131022git08767a.fc27
        old:
opensuse:
    ----------
    exim:
        ----------
        new:
            4.86.2-20.1
        old:
    libgc1:
        ----------
        new:
            7.2d-11.3
        old:
    libgmime-2_6-0:
        ----------
        new:
            2.6.20-6.3
        old:
    libgpgme11:
        ----------
        new:
            1.9.0-1.3
        old:
    libkyotocabinet16:
        ----------
        new:
            1.2.76-16.1
        old:
    liblua5_2:
        ----------
        new:
            5.2.4-6.1
        old:
    libmysqlclient18:
        ----------
        new:
            10.0.34-32.2
        old:
    libnotmuch4:
        ----------
        new:
            0.22.1-3.17
        old:
    libpq5:
        ----------
        new:
            9.6.8-15.1
        old:
    libspf2-2:
        ----------
        new:
            1.2.10-8.1
        old:
    libtalloc2:
        ----------
        new:
            2.1.10-2.3.1
        old:
    libxapian22:
        ----------
        new:
            1.2.21-5.3
        old:
    mutt:
        ----------
        new:
            1.8.2-1.7
        old:
    mutt-doc:
        ----------
        new:
            1.8.2-1.7
        old:
    mutt-lang:
        ----------
        new:
            1.8.2-1.7
        old:
    perl-Expect:
        ----------
        new:
            1.32-5.1
        old:
    perl-IO-Tty:
        ----------
        new:
            1.12-6.1
        old:
    python-curses:
        ----------
        new:
            2.7.13-27.3.1
        old:
    python-urwid:
        ----------
        new:
            1.3.0-6.2
        old:
    urlscan:
        ----------
        new:
            0.8.3-1.2
        old:
    urlview:
        ----------
        new:
            0.9-737.1
        old:
    w3m:
        ----------
        new:
            0.5.3.git20161120-163.3
        old:
ubuntu.lxd:
    ----------
    imap-client:
        ----------
        new:
            1
        old:
    libgpgme11:
        ----------
        new:
            1.10.0-1ubuntu1
        old:
    libtokyocabinet9:
        ----------
        new:
            1.4.48-11
        old:
    mutt:
        ----------
        new:
            1.9.4-3
        old:
opensuse:~ #

Creating the Ultimate Container Playground: LXD on Kubic

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Introduction

LXC (Linux Containers) are whole-system containers. They are meant to be able to do just about anything you can do with a VM with a percentage of the system resources and and a tiny startup time.

During Installation:

During installation, you can pretty much choose defaults for everything except you will need to create two additional btrfs subvolumes and if you gave your VM more than 30G of space, you will need to specify that manually because the installer will only recognize 30G by default.

Create btrfs subvolumes for:
/snap
/media

After Installation

Add the snappy repo

sudo zypper addrepo --refresh http://download.opensuse.org/repositories/system:/snappy/openSUSE_Tumbleweed/ snappy

Create the last subvolume needed for snappy

sudo btrfs subvolume create /var/lib/snapd

Install snappy

sudo transactional-update pkg install snapd

reboot

Enable and start the snapd service

sudo systemctl enable snapd && sudo systemctl start snapd

Install the LXD snap

sudo snap install lxd

Setup

Initialize LXD

lxd init (choose defaults to make life easier the first time)

Create your first LXC container. The first time you create the container, LXD will download the image. After that any new containers build from that image will start very quickly.

lxc launch images:opensuse/42.3 opensuse

Enter into your first container

lxc exec opensuse bash

Why are there toilets on my openSUSE wallpaper?

JSEvans4 Comments

First of all, the entire wallpaper is here:

On the right-hand side, there are these cool line-art cad drawing with Geeko in the middle. The problem is that these aren’t just just random lines nor are they circuits boards or anything like that. These are architectural blueprints. There are 5 full bathroom and a small piece of a 6th. There’s also a couple of conference rooms.

My proof:

Why do I care?

I think it’s hilarious. It’s a strange decision for a wallpaper and I bizarre easter egg to find.

My SSH Trick

JSEvans3 Comments

10 hours of jetlag and rainy afternoon naps don’t mix. It’s 2 minutes to 2AM here in Provo, UT and I can’t sleep so I’m blogging.

I want to ssh into a machine that doesn’t have any external IP. In the case of my situation at home, I get a 192.168… IP from my ISP because of a shared connection. In other cases, I have VM’s with natted IP’s that also have no direct way in.

I could pay for a VPN service and vpn into these machines, but instead I’m using a free way of doing it. I use Tor.

Here’s how it works, the Tor service reaches out to the Tor network and is listening on port 22 (or whatever port I choose for ssh) for incoming requests. I use “torsocks ssh zzzzzzzzz.onion” from my laptop and I am in. This bypasses the external internet and gives me a pretty secure route from my laptop to my home machine only via Tor.

Here’s how I set it up with OpenSUSE

On your remote or inaccessible server:

$ sudo zypper in tor

This installs the tor service and the torsocks proxy app.

$ sudo vim /etc/tor/torrc

Uncomment the following lines:

HiddenServiceDir /var/lib/tor/hidden_service/
HiddenServicePort 22 127.0.0.1:22
$sudo systemctl start tor

The service is now started and you should have a new .onion address

$ cat /var/lib/tor/hidden_service/hostname

On your local machine/laptop/etc:

$ sudo zypper in tor
$ sudo systemctl start tor
$ torsocks ssh xxxxxxxxx.onion

This is a cool trick. Of course you can use it on any server/VM/etc even if they do have accessible IP’s. In those cases, I suggest that you close the firewall on port 22 and allow it to be only accessible via Tor. There is no need to have extra ports open to the internet.

Using Tor is a great way to add security to your network communication. In addition to the SSH encryption, the packets have additional encryption due to the nature of how Tor works.

About privacy. You also benefit from the inherent privacy of the Tor network which you might not get if you believe that your ISP, etc is gathering data on it’s users. If they are monitoring packets are that interested, they can probably see that you are using Tor but they can’t see what you are doing or where you are connecting. Is it more or less private that using the Tor Browser? I don’t know. It’s worth looking into. My feeling is that since ssh is low-bandwidth, has no possible extra problems that browsers have such as javascript, vulnerabilities, etc. it probably is as safe or safer.

Anyway, I hope this helps people out if you’re like me and have to make do with an ISP that makes using the web just a little harder.

One last thing. Tor is more laggy than a straight connection. You’re not doing anything wrong, it’s just a side-effect of how this all works.

Stupid Script

JSEvansLeave a comment

I just cobbled this script together to make starting up VirtualBox VM’s a little easier when remote.

for a in `vboxmanage list vms | sed 's/^"\(.*\)".*/\1/'`; \
do echo $a && vboxmanage showvminfo $a | grep -c "running (since" ;done

This will give you a list of all of your VMs. Followed by a 1 if it is powered on or a 0 if it isn’t. If your VM name contains a space, this won’t work. In that case, the following will give you just the list:

vboxmanage list vms

You can then run the following to get all of the information and grep out the “since”

vboxmanage showvminfo "My VM"