Why unix
Some people might ask that in today's day and age, why do we still use command lines and not GUI's. The simple answer has to be along the lines of keep it simple stupid. The fewer the lines of code, the lesser the chance of something failing. qmail is based on the idea that software should be built up from many small programs doing small and simple tasks that fit together to create a larger purpose. The software has well defined inputs and outputs. This is pretty much the essence of unix software.
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apache
A colleague of mine at work noted that one of the boxes has had an instance of apache running since Jul 1999, he did point out that this might be a world record for length of time that Apache HTTP server.
Apache is designed very well and efficiently with a very modular approach. The inputs and outputs for each module are very clear and well defined. It's no surprise that uptimes for a single process of this duration can be achieved on a unix platform.
[edn@www0-rth ~]$ uname -a SunOS www0-rth* 5.7 Generic sun4m sparc SUNW,SPARCstation-20 [edn@www0-rth ~]$ uptime 6:22pm up 3958 day(s), 4:54, 3 users, load average: 0.10, 0.09, 0.08 [edn@www0-rth ~]$ ps auxwww | grep apache nobody 744 0.2 1.1 3196 1332 ? S 17:30:19 0:03 /usr/local/apache/bin/httpd -f /etc/httpd.conf edn 1100 0.2 0.5 880 568 pts/2 S 18:23:00 0:00 grep apache nobody 958 0.2 1.1 3180 1304 ? S 18:08:55 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 1081 0.2 1.1 3180 1304 ? S 18:22:33 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 805 0.1 1.1 3196 1332 ? S 17:40:34 0:02 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 957 0.1 1.1 3180 1304 ? S 18:08:33 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 1016 0.1 1.1 3180 1304 ? S 18:14:24 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 954 0.1 1.1 3180 1304 ? S 18:05:52 0:01 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 981 0.1 1.1 3180 1304 ? S 18:09:23 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 990 0.1 1.1 3180 1304 ? S 18:12:37 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 1058 0.1 1.1 3180 1304 ? S 18:20:12 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 735 0.1 1.1 3196 1332 ? S 17:29:59 0:03 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 712 0.1 1.1 3180 1304 ? S 17:26:58 0:03 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 798 0.1 1.1 3196 1332 ? S 17:39:39 0:02 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 866 0.1 1.1 3180 1304 ? S 17:52:36 0:01 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 1027 0.1 1.1 3180 1304 ? S 18:15:35 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 1060 0.1 1.1 3180 1304 ? S 18:22:02 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 1017 0.1 1.1 3180 1304 ? S 18:14:41 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 1029 0.1 1.1 3180 1304 ? S 18:17:35 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 787 0.1 1.1 3180 1304 ? S 17:39:13 0:02 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 1026 0.1 1.1 3196 1332 ? S 18:15:11 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 955 0.1 1.1 3180 1304 ? S 18:06:10 0:01 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 895 0.1 1.1 3180 1304 ? S 17:56:54 0:01 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 982 0.1 1.1 3180 1304 ? S 18:09:55 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 989 0.1 1.1 3180 1304 ? S 18:12:13 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 991 0.1 1.1 3180 1304 ? S 18:13:53 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 992 0.1 1.1 3180 1304 ? S 18:13:54 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 1028 0.1 1.1 3180 1304 ? S 18:16:27 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 745 0.1 1.1 3180 1308 ? S 17:31:04 0:03 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 774 0.1 1.1 3196 1332 ? S 17:38:58 0:02 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 993 0.1 1.1 3180 1304 ? S 18:13:54 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 956 0.1 1.1 3196 1332 ? S 18:08:17 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 806 0.1 1.1 3180 1304 ? S 17:41:06 0:02 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 1098 0.1 0.7 3164 856 ? S 18:22:51 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf nobody 1059 0.1 1.1 3180 1304 ? S 18:21:45 0:00 /usr/local/apache/bin/httpd -f /etc/httpd.conf root 2560 0.0 1.7 3140 2120 ? S Jul 15 17:11 /usr/local/apache/bin/httpd -f /etc/httpd.conf [edn@www0-rth ~]$ ls -al /proc/ | grep 2560 dr-x--x--x 5 root other 736 Jul 15 1999 2560
networking
With UNIX and Linux it's very possible to LD_PRELOAD a library that wraps all the network syscalls to interface with a SOCKS library. I don't even know of anything in Windows remotely close.
Consider that you have a corporate network behind a firewall. Using UNIX all you need is ssh and something such as tsocks. tsocks can pass all the network system calls through ssh -D 1085 to pass all your programs through the firewall that you're connecting to. This makes life easy for any road warrior.
When using a program that has to interface with a set of system calls such as disk or network that require a layer of alteration (such as socks or file revisions) it's far easier to use LD_PRELOAD to interface with that change in a simple way without recompilation of the software.
The best mail client that I've ever used is named mutt, it has a text console interface, which means you can run it remotely over ssh without any real concerns for bandwidth.
automation
One of the things that I've always disliked about Windows and other systems of that nature is that most of the automation can only be done by linking to DLL's (DLL Hell) and attempting to call functions from there, even for rudimentary tasks. However, in UNIX/Linux land there are lots of things that make automation a really simple task. Take screen for example and if that's no use there's always perl/awk :)
documentation
In Windows you're primarily stuck with MS Office (or WordPad). That's what MS want's you to buy into. Even when MS attempts to convince the public they're cooperating and interacting in open formats they just can't do it right.
On UNIX/Linux there's a wonderful thing called LaTeX which can be used to output in a variety of formats.
What's very interesting though is that things which people can do on the command line easily and freely with Linux (such as versioning and scripting) MS try and put into a documenting system and things become difficult to understand since its very hard to see the inner workings of the document.
Having the document in text format with structure makes a piece of work easier to manage and easier to distribute and track changes with a diff tool, better still with subversion which makes for very easy collaboration.
Other alternatives: groff, openoffice.org, abiword, lyx.
graphical documentation
graphviz and xfig are processed from text files, the process outputs a graphic binary. This, just like the text processing tools above make for very easy version control. There is also Dia which is very useful and easy to use, however, it is not so easy to collaborate.
Another really great way to display information is with gnuplot which takes parameters as values (when reading from a file) and then can display it graphically. This comes into big effect when you're monitoring or collecting statistics.
interested in unix
If you're interested in UNIX and have never given it a go, why not get a free shell account from the DMOZ directory?
why linux and not unix
My primary reason for choosing Linux above a more traditional UNIX (*BSD or OpenSolaris) is the availability of ionice. This is a scheduling tool for processes on Linux to run in priority groups, either when IO is available, realtime or normal. This is something that makes Linux more of a QoS choice. Even if the system has just one user, then that user may choose to have processes backgrounded in favour of more UI intensive tasks.
why not vista
Basically, tonight, ten minutes wasted looking at boot up screens, spinning thumbs.
Above I made a tiny error in saying that there is no way to socksify an application. It turns out there is an application that can do this, it just appears that it can't do "big" things like Internet Explorer or Firefox, which is a shame as they're quite heavily used.
There are other contributing factors to why you might not want to use Windows as your server or desktop operating system:
- WordPad vulerable to remote code execution
- DLL library loading allows attackers to use libraries in the current working directory
There are other things that you should consider if you're thinking about switching OS, particularly if you're going to switch from something like MacOS to Windows or Linux/BSD to Windows.
In my opinion I personally don't think Windows is ready for the desktop. The main contributing factor for this is my strong belief that the end user should not be be left on the internet with an insecure OS and Windows out of the box is very insecure.
If an end user does not have much computing awareness then Windows is not the ideal OS. Any other OS is ideal and the choice the end user goes with probably should then be dictated by cost.
Typical faults are:
- spyware/malware
- viruses
- worms
The above are mainly due to flaws in the OS or browser. Even with something like Firefox there are still potential problems due to the end user clicking a run dialog.
The best route around this is to give the end user an OS which is probably not going to be able to execute malware.
On the other hand, linux has hardly any viruses. Thanks to the author of that page for compiling such a detailed list of viruses.
getting back some time
Another annoyance for me is the combination of the "run" registry keys and the annoyingly long time it takes to start up and give control to the user and the amount of time takes to shutdown.
Despite repeated cleaning of the "run" registry keys I've not found it a practical means of reducing the startup times.
Packages are yet another huge disadvantage of Windows, despite people touting about software availability for the MS platform its surprisingly difficult to install programs without seeking their publishers web sites.
codecs
With Linux it's often a simple case when watching a video through a player for the player to ask you if you wish to install additional codecs and offer download choices.
On Windows however the options are not presented to the user (as I have found out with Windows XP and Vista) and the user has to attempt to locate codecs for themselves. This often leads to downloading of setup packages and other programs which will require administrator privileges to run. This has the scope to return the computer to an unknown state as it is not easy to verify the authenticity of the program.
Examples of this are here
updates
I've come to dislike the update mechanism within Windows. It appears to me that it's not correct to term this 'update' because it really doesn't 'update' the system, it can only move it forward a single step. I know this since for the past week each and every time we have booted a Vista laptop it has required more staged update reboots.
If this were truly an 'update' then it should only happen once (just like it does with a Linux package update).
Many times when using Vista or XP I've found my tasks delayed because the system refuses to do anything until the update has been applied. In worse cases I've found the network drivers are disabled part-way through applying updates, rendering the system unusable.
cd writing
There comes a point when I have to give up with Windows. My corporate laptop at work which has a "well looked after" Windows XP build, and works as a glorified MS Exchange client also has a DVD Writer.
It's a very good laptop, it was given to me three years ago when I started work with this company. The laptop has a very good hardware build, it's case is very sturdy and I don't think they come much better.
However, when blank media is inserted into the DVD drive for some reason Nero thinks there is a session already on the disc, I can't find out what has the session open (there's no fuser or similar for this), which is really quite a tricky situation.
It's not really worth my time to try and figure this out as I don't have Admin rights on it, so a simple dual boot or pendrive solves the problem with Ubuntu and wodim.
This sort of thing makes me eternally frustrated with Windows as it's pretty much impossible for me to work with in a engineering role where you have to shovel data from point A to point B. Sounds simple, but it's just not fit for purpose.
data recovery
Imagine the situation, you're up late working on a project and you desperately have to get it in on time tomorrow and the disk starts making really weird sounds. So what do you do?
- Drag and drop all your folders on another disk?
Oh you've only got one OS disk and the OS starts to error at you. Bummer.
Fear not, whatever situation you're in, getting a command prompt open in UNIX and running a dd with the bad disk source and output to another disk is the safest thing you can do right now. Taking the raw contents of the disk will at least allow you to mount and possibly boot the disk on more reliable hardware. If you don't have a blank hard disk/usb then taking a image to file will probably suffice for now, maybe pipe through a gzip if space for an uncompressed image isn't available.
One thing that's almost guaranteed to cause problems would be attempting the same thing with a Windows disk. Even if you can read the disk and mirror to another, you can probably bet your savings that Windows will blue screen on you.
backup and restore
In brief, you can backup your entire system using a couple of routine commands in your crontab file, restoration is just as easy.
# dump -0 -f - /dev/sda1 | gzip ...
Restoring is pretty much just the reverse
# restore -rf
packages
One thing I've forgotten to mention so far on this page is packages and later I will mention source code.
Packages are normally pre-compiled pieces of software which contain among other things usually a pre and post install script. These little scripts often tweak systems to accommodate the new software.
Debian is my favourite distribution to use on the desktop and the server. There are a variety of reasons for this choice, one of the biggest reasons for this choice is that the distribution repository contains just about all the software that I could ever want to install in a pre-compiled format that will work just perfectly with my system.
source code
Failing the above on some rare occassions I'll want to install something from source code. It's almost always a very straightforward process.
wget thing.tar.gz
tar zxvf thing.tar.gz
cd thing
./configure --{exec-,}prefix=~/source-build && make && make install
It's a few simple steps to get the job done. The advantage of this is that should I wish to make changes and send those to the author it's very simple to do that.
log files
It still amazes me how hard it is to see what's going on when you do something in Windows. For instance, there's no means of doing anything like strace or tcpdump on a base Windows install, sure the community provide a means, but this isn't aways available without having to "trust" a possibly rogue download site to provide you with a copy.
So, if you can't use tcpdump or strace, what can you do to diagnose a fault with a program? Without awk/grep and syslog messages what useful tools are there to make your life easy?
other pages
- 20061224_10_Reasons_to_Switch_to_Linux
- 20061203_10_Reasons_to_Switch_to_Linux_from_a_Former_Windows_User's_Perspective
- 20070715_Linux_User_Names_10_Reasons_to_Switch
- 20070111_Reasons_to_Switch_to_Linux
- 20070828_New_Windows_Rootkits_Another_Reasons_to_Switch_to_Linux
- 20071204_Windows_Vista_Service_Pack_1_Give_More_Reasons_to_Switch_to_GNULinux
- 20080918_Reasons_to_Switch_to_GNULinux_Ubuntu_Specifically
- 20090210_Lots_of_Good_Uses_to_GNULinux_and_Reasons_to_Switch
- 20111213_Get_Involved
