Brian Smith's AIX / UNIX / Linux / Open Source blog
I had a couple of AIX related articles published this month. Here they are in case you haven't seen them yet:
Scripting IBM AIX LPAR builds from A to Z in an IBM PowerVM environment (IBM developerWorks)
Understanding Power System LPAR Profiles - (POWER IT Pro)
Guns and UNIX Admins have some similarities. Guns, when properly used, are very powerful tools that can do a lot of good, much like a sysadmin. However, if you are careless as a sysadmin, or careless with a gun the results can be devastating and even irreversible.
One of the basic NRA gun safety rules is to "ALWAYS keep your finger off the trigger until ready to shoot." People who break this rule often end up accidentally shooting family members because when startled or surprised your instinct is to clinch and if your finger is on the trigger you are going to pull it whether you are ready or not.
This same concept directly applies to being a UNIX/Linux sysadmin. Being logged in to a root user prompt is equivalent to having your finger on the trigger. One mistake at this point, and you can cause major damage. Commands such as "rm" are extremely unforgiving and very easy to make mistakes with.
I have seen sysadmins in the habit of right when they log in to a server the first thing they do is switch over to the root account, regardless of what they need to accomplish. This is a horrible habit to get in to. You should only switch to the root prompt when absolutely necessary. If you can perform whatever task you need to do as a regular user, then do that. If only part of what you need to do requires root access, only do that one part from the root prompt and then go back to the normal user account.
You can perform a ton of functions when logged in as a regular user account such as viewing almost all of the system configuration, information about filesystems, running processes, performance information, etc. And when logged in as a regular user there is very little damage you can do to the system if you make a mistake. If being logged in as the root user is like having your finger on the trigger on a loaded gun, then being logged in as a regular user is like having a Toy Nerf Gun - you probably aren't going to do much harm.
This especially applies if you are writing and testing scripts. Never test a script as the root user unless you are on an isolated, throw away, lab server. Testing scripts as the root user is equivalent to playing with a gun - something or someone is probably going to get hurt. One method that can help with this is Writing scripts that don't actually do anything.
So remember the next time you see the root # prompt... You essentially have a loaded gun in your hand with your finger on the trigger. You need to be careful and make sure you are ready to fire and think through each step of what you are doing.
The Dvorak keyboard is an alternative keyboard layout that arranges the keys in a more efficient way:
(Image source: http://en.wikipedia.org/wiki/File:KB_United_States_Dvorak.svg, public domain)
The Dvorak keyboard layout was created in 1936 and was designed to be a more efficient layout than the normal QWERTY layout. Every letter is moved from its original QWERTY position except for "A" and "M". For more information on Dvorak and its history, see this Wikipedia article.
If you look at a QWERTY keyboard you'll notice it is possible to type "TYPEWRITER" using only the top row of keys. Coincidence? I personally think not. The Dvorak keyboard is so interesting to me because it was designed to be a good keyboard layout for typing. QWERTY? Not so much... According to Discover Magazine, 70% of your normal keystrokes are done on the home row with Dvorak, versus about 32% on the home row for QWERTY. There is a ton of information out there on the internet comparing Dvorak to QWERTY so I won't repeat it here, but if you are interested do a search on Google.
The world record holder for English language typing speed, Barbara Blackburn, typed on a Dvorak keyboard.
I have been using Dvorak exclusively for the past 8 years, and wanted to share my experiences using it as an IT person.
Here are the benefits I've found of using Dvorak:
Here are some things to consider if you switch to Dvorak:
In addition to Dvorak, there are some other keyboard layouts out there as well such as the "Colemak" layout, but these are not as standardized as Dvorak. But before you decide to switch to a different keyboard layout you should research others and come to your own conclusion on which is the best option for you. For me, it was Dvorak due to its relative widespread recognition, support in all modern OS's, and ANSI standardization.
Being a Dvorak typist can really be a pain sometimes when you need to use other peoples computers or when you run in to an application that doesn't use the OS keyboard settings. But it is so much more comfortable for me that it is worth it. If I had to do it all over again I would still make the switch to Dvorak.
The last two weeks there have been excellent presentations by Rosa Davidson about Virtual Processors on the AIX Virtual Users group. If you haven't seen these, check them out at https://www.ibm.com/developerworks/mydeveloperworks/wikis/home?lang=en#/wiki/Power%20Systems/page/AIX%20Virtual%20User%20Group%20-%20USA
One of the things Rosa covered in the presentation was making sure you understand your ratio of Virtual Processors to Cores on the entire frame and understanding the ratio of Entitled CPU to Virtual Processor on each LPAR.
I think this is a great idea, and wrote a script to automate the process of creating a report that shows this information.
The script creates a report like this:
You run the script from AIX or Linux server that has SSH keys setup with your HMC. You then just specify the HMC name (or user@hmc) with the "-h" flag and the managed system name with the "-m" flag.
Here is the link to download the script: https://www.ibm.com/developerworks/mydeveloperworks/blogs/brian/resource/vp-report.tgz