During the RIPE 55 meeting in Amsterdam last week, a community statement was issued on the future of IPv4. Basically they say that we will run out of IP addresses in two to four years and we need IPv6.
To drive the point home, Gary Feldman performed a song titled “The Day the Routers Died” (sung like “bye bye american pie”).
You are probably used to seeing Internet addresses that look like these
http://www.paranoidagnostic.net/category/sysadmin
cloned.milkmen@paranoidagnostic.net
The first is called a URL and is used for web pages, and the second is an email address. While these addresses both look quite different and are used for different purposes they both contain something called a Domain Name (or DNS name). In this case the domain name is “paranoidagnostic.net”.
Domain names are used to organize Internet addresses in an orderly way and to delegate authority for the creation of Internet addresses.
Internet domain names are organized according to a hierarchy. Levels in the hierarchy are denoted by periods in the domain name. When you read a domain name from left to right, the left is the lowest level and the right is the top-most level of the hierarchy. The lower levels are referred to as subdomains of the higher level domains./p>
For example, the DNS name “www.paranoidagnostic.net” shows three levels of the hierarchy:
The top-level domains (TLDs) are very important. There are only a limited number of top-level domains and they are controlled by various authorities around the world. There are generally three types of top-level domains: US-only, country specific, and generic.
US-only TLDs are only available to US institutions and are under tight control. For example, “mil” is only for the US military, “gov” is only for the US government, and “edu” is only for accredited US post-secondary institutions.
Country-specific TLDs have two letter codes that usually (but not always) correspond to international standard two-letter codes for those countries. For example, the TLD for Canada is “ca” and the TLD for the United Kingdom is “uk”.
generic TLDs are usually available to anyone in the world. “com”, “net”, “org”, “biz”, “info” and a growing list of others are in this category.
TLDs are created by the Internet Corporation for Assigned Names and Numbers (ICANN). Regular organizations cannot have TLDs. Individual people or organizations can obtain subdomains of TLDs. ICANN assigns a separate authority to govern each TLD and those authorities set their own rules about who can and cannot have a subdomain.
For example, the “UK” TLD is governed by Nominet. Nominet administers all UK subdomains and sets rules for how they can be named. In the UK TLD commercial organizations are put in a further subdomain of “.co.uk” and educational institutions in “sch.uk”. For example, a phone company in the UK could get a domain of “myphonecompany.co.uk” but not “myphonecompany.uk” or “myphonecompany.sch.uk”. In the UK authority for some domains is delegated to an organization other than Nominet. For example, subdomains of “parliament.uk” have their own system of rules.
Contrast that with the “CA” TLD. “CA” is governed by an organization called the Canadian Internet Registry Authority (CIRA). It does not have a special subdomain for commercial organizations. A phone company in Canada could obtain “myphonecompany.ca” for a domain name. Similar to the UK TLD government subdomains are restricted. Only the Canadian Federal Government can obtain subdomains of “gc.ca”.
Some countries have turned over control of their TLDs to commercial companies that allow anyone in the world to use them. For example “TV”, “FM”, and “AD” are all country-specific TLDs that are administered by commercial organization that treat them like generic TLDs.
It is often very helpful to know who governs a TLD and what their policies are. For example, if you find a website might appear to be for a institution in a specific country and have a subdomain that appears from that country. In the UK and Canada (“.ca”) you could be sure that any site that ends in “.parliament.uk” or “.gc.ca” are associated with the government. But a website in other subdomains may not be authentic. Each country has its own authority and own rules so verifying who is real and who is not can be challenging.
Fortunately, the Internet Assigned Numbers Authority (IANA) keeps a list of all of the TLD authorities. You can find the contact information, usually including website addresses, for every TLD on that list. You can then contact the listed authority to find out what their policies are.
Note: The Internet’s domain name system is referred to as DNS (Domain Name System) and defined by many RFCs (Internet standards).
I am currently having a surreal system administration experience: I am the sysadmin for a Wiki project in Chinese. I do not read, write, or speak Chinese and the Wiki is intended for use by the local Chinese community and is thus localized in Chinese. This has been the strangest thing for me. When I login to the software, I cannot even read the menus, and there are so many decisions that would normally be trivial that are now strange and difficult.
The project is to catalogue my local public library’s collection of Chinese books in a wiki. The library doesn’t catalogue the foreign language books (probably because it cannot). I am using MediaWiki (same software used for Wikipedia) which already has localization for many languages including at least 5 Chinese options.
One significant problem is trying to choose the right localization. So far, no one I know who actually speaks Mandarin Chinese can tell me what pros and cons there might be to picking one over the other. As a sysadmin, normally it would be my job to tell people what the pros and cons of one technical choice over another are. In this case I feel like I’m in an alternate reality. I am the right person for this job, but also completely unqualified!
MediaWiki seems to be the right choice for this project, not only because of its open editing, version tracking, and simple-but-effective content markup system, but also because it natively understands what an ISBN is. MediaWiki scans any text entered for strings that start with “ISBN” and end with a number and some dashes. If it sees such a string, it turns that into a link to its own internal system for linking to places that can give you more information about an ISBN. This is really good for a book-based library project.
I intend to write another component to magically identify book’s barcodes in the same way it does ISBN numbers, so that we can automatically link to the library’s catalogue. Thus someone can have one click access to putting a hold on an item.
Stranger than all of these other things, is that is a project I created. Normally, I would be writing up all kinds of “about” pages and help for the users. I suppose I will do that in English, but I always hesitate because it is, after all, supposed to be in Chinese. I just hope my translator is good!
Losing the data on your hard disk can be tragic. This video demonstrates one of the warning signs that your hard disk is about to die leaving you with little hope of every getting your data back. A common way for hard disks to “go bad” is for a mechanical failure to occur. Inside your hard disk are some disks that contain your data that spin rapidly, and some “read/write” heads at the end of a moving arm. The arm moves the heads back and forth over the surface of those spinning disks so that they can jump to the data you want to read or write. The movement of the read/write heads is controlled by a magnetic mechanism that is supposed to prevent the heads from going to far to the outside or inside of the disk.
If the mechanism controlling the arm starts to fail, there will be warning signs first! One of the warning signs is that you start to get disk errors more often. But just prior to the complete failure of the disk you might start to hear loud clicking noises and the occasional “bouncing” noise. These are bad signs. Some drives sound like they are clicking normally, so it helps to see and hear and example of a drive that has failed to know the noises you can expect. This video demonstrates that.
I have opened the casing to show the motion of the traveling arm. Notice that the noise appears to coincide with the heads hitting the black plastic on the outside of the disk or the metal circle at the center of the disk. The noise is not generated by the heads hitting anything. In fact, the noise is generated by a small piece of plastic located under the metal housing visible in the top left corner of the hard disk shown in the video. If you watch carefully, you can see a flash of motion near the top left edge of the disk during the video. When the arm moves toward the outside and goes to far you will hear the bouncing noise. When the arm moves to far inside the disk, you will hear the clicking noise.
A word of warning. NEVER OPEN YOUR HARD DISK. It will never work again if you do. This demonstration was done because the hard disk was already ruined and unrecoverable.
These noises sometimes occur just before it is too late; just before the disk dies forever. If you reboot, your computer’s BIOS may not recognize the drive. You will very likely hear those clicking noises repeated over and over and the occasional “bouncing” noise (heard at the very beginning of the video. Mechanical failures are not the kind of thing you can fix on your own. A data recovery company might be able to get your data back, but they will need to open the hard disk and operate on it in a clean room (the air and dust can ruin it).
So, what do you do if you hear the clicking and bouncing noises?
If you cannot backup the data or the backup fails, you can do this:
Last Saturday (April 28, 2007) I gave a presentation at the Alberta Library Conference (ALC 2007) titled, “How to Get the Technical Support You Need.” I think many, if not most, people have had negative experiences trying to obtain technical support. Contacting a helpdesk leaves people feeling frustrated, ignored, or like they are getting the run-around. After dealing with tech support, people often feel as if they are expected to learn new technical skills or adopt a new language of three letter acronyms just to get a little help.
My presentation rejects the idea that people need to learn technical skills just to get a techie to help them. Instead I introduce management and communication skills that can be used to obtain better tech support.
The presentation is divided into three sections. First, I explain how helpdesks generally work following the Limoncelli (1999) 9-step/4-phase model. Second, I explain how to write a great support request that has enough information that tech support won’t need to ask a lot of question and give you the run-around. Last, I present some rules-of-thumb for effectively managing communication with tech support for those worst-case scenario problems.
All of the ideas are based on my nearly 15 years of experience in giving and getting support. The rules and advice are inspired by some of my worst-cases in getting support and I show how my advanced technical skills are not enough to allow me to get tech support: Managing communication is the key to getting good support.
The slides for my presentation can be downloaded and they contain commentary in the “notes” field that can be viewed or printed if you open the file in Powerpoint or OpenOffice. The presentation is covered by a Creative Commons license and can be redistributed and remixed as long as attribution is provided and you share-alike.