Entries Tagged as 'Computers'

Dynamic Sitemap

About two years ago I wrote a program that created a sitemap from a local copy of my web pages (I also wrote an automation wrapper so that I could do all my web sites along with other mundane tasks reliably).

When I installed WordPress over a year ago I really liked the fact that the sitemap plug in was capable of dynamically creating a sitemap when a request was made; and I set it as a goal to implement that on my web site.

Well, yesterday that goal was realized.

I wrote a simple PHP script that takes some meta information and creates a sitemap, either uncompressed or compressed based on what is requested.  I used a rewrite rule in my .htaccess file to allow search engines to continue to request the familiar sitemap.xml and/or sitemap.xml.gz file.

Now I don’t have to worry about creating and deploying a sitemap file when I change a file; I only have to make sure that the meta information is updated when I add or remove pages.  Plus, I incorporated the concept of dynamic pages, so that the sitemap can accurately report fresh content.

At the moment I haven’t decided if I’m going to “publish” this code or not.  It’s likely I will once I clean it up and actually test it more completely.  Like I said, it isn’t rocket science – it just takes a little knowledge of what a sitemap is, and you can get everything you need from sitemaps.org; a little ability in PHP, and a basic understanding of how to write a re-write rule for Apache.

Originally posted 2010-02-23 01:00:50.

Virtualization Solutions

On windows there’s basically three commercial solutions for virtualization, and several free solutions… wait one of the commercial solutions is free (well when you buy the operating system), and the other is partially free…

  • Microsoft Virtual PC (runs on both servers and workstations)
  • Microsoft Virtual Server (runs on both servers and workstations)
  • Microsoft Hyper-V (runs only one Windows Server 2008)
  • Parallels Workstation (runs on workstations)
  • Parallels Server (runs on both servers and workstations)
  • VMware Player (runs on both servers and workstations)
  • VMware Workstation (runs on both servers and workstations)
  • VMware Server (runs on both servers and workstations)
  • Citrix (aka XenSource)

For Intel based Mac you have commercial solutions

  • Parallels Desktop
  • Parallels Server
  • VMware Fusion

And for Linux you have the following commercial solutions, and many free solutions (Xen being one of the leaders)

  • Parallels Desktop
  • Parallels Server
  • VMware Player
  • VMware Workstation
  • VMware Server
  • Citrix (aka XenSource)

And for bare metal you have

  • Parallels Server
  • VMware

 

I’m not going to go into details on any of these, I just wanted to give at least a partial list with a few thoughts.

If you’re new to virtualization, use one of the free virtualization solutions.  You can try several of them, and many of them can convert a virtual machine from another vendor’s format to it’s own, but learn what the strengths and weaknesses are of each before you spend money on a solution that might not be the best for you.

Microsoft Virtual Server has some definite performance advantages over Microsoft Virtual PC… there are some things you might lose with Virtual Server that you might want (the local interface); but Virtual Server installs on both desktop and workstation platforms, so try it.

For Mac I definitely like Parallels Desktop better than VMware Fusion; but you may not share my opinion.  VMware claims to be faster, though I certainly don’t see it.  And I might add, that if you have a decent machine you’re running virtualization software on, fast isn’t going to be the number one concern — correctness is far more important.

Also, with each of the virtualization systems, hosts, and guests there are best practices for optimizing the installation and performance.  I’ll try and write up some information I’ve put together that keep my virtual machines running well.

For the record, I run Microsoft Virtual Server 2005 R2 (64 bit) on Windows Server 2003 R2 x64 SP2, and on Windows Vista Ultimate and Business x64 SP1; works well.  And I run Parallels Desktop v3 on my Macs.

For the most part my guests are Windows XP Pro (x86) and Windows Server 2003 (x86); I don’t really need 64-bit guests (at the moment), but I do also run Ubuntu, Debian, Red Hat, Free Spire, etc linux…

Like I said, figure out your requirements, play with several of the virtualization systems and spend your money on more memory, perhaps a better processor, and stick with the free virtualization software!

Originally posted 2008-05-18 20:25:18.

Nothing but the necessities…

In a school district that is struggling to keep teacher’s it’s amazing that that the Santa Rosa County Florida School District can find the money (and need) for 90 iPad2s for administrators (it’s also amazing that there are 90 administrators in a  county with only about 150,000 residents).

I’m glad to see that my tax dollars are well spent on essential items to insure that today’s school children will be properly educated and that the administrators responsible for overseeing that education will have new toys at the disposal to sit mostly unused in their desks — after all, an edict has been issued by the school district that these devices are only to be used in a professional capacity.

I wonder, will it be grounds for immediate termination the first time a games is played on,, a facebook post is made from or personal email is sent via one these essential educational tools — inquiring minds want to know.

My personal feeling would be this money would be better spent offsetting the $4.4 million dollar shortfall for the 2011-2012 school year that is necessitating the layoff of teaching staff — of course, why should I be surprised about iPad2s for administrators, after all most of them just got raises to address the inequities in their pay (I guess they couldn’t afford their own iPad2s — though they seem to expect teachers to buy a great deal of supplies for their classrooms out of their considerably smaller salaries).

Originally posted 2011-08-15 02:00:22.

Swarms

No, not a swarm of bees, wasps, hornets, or yellow jackets — I’m talking about file sharing technology.

First, there’s absolutely nothing illegal or immoral about using file sharing technology for file sharing and distribution, just as there’s nothing illegal or immoral about using hyper-text (http) or file transfer (ftp) technology.  It all has to do with the content you’re trying to exchange, not the system you’re using to exchange it.

There are many legitamate uses for BitTorrent and other P2P technologies.  Here’s a perfect example.

A small company has a number of offices spread throughout the world, and no one location has an internet connection with significant bandwidth (let’s say for argument, they all had a high end class of DSL service, but none of them have fibre).  This company would like to distribute it’s trial software, but because of the economics can’t afford to pay for additional bandwidth or for a content delivery system — they could opt to “aggragate” the bandwidth of all of their offices by providing a torrent and running torrent servers at each location — that would allow the nodes with the most bandwidth available to satisfy requests, and any individuals who had downloaded the software and elected to continue seeding would be able to source it as well.  While no one individual might get the software as quickly (though that’s not necessarily true), many more people would be able to get the software sooner, and at no additional cost; thus the company could meet it’s budgetary constraints and might not have to consider increasing the amount they need to charge for the software to cover operating expenses.

Swarming technology is real, it’s practical, and it’s a solution for a number of problems.

Swarms are highly fault tolerant, they’re highly distributed, and they dynamically adjust to changing conditions…

While any technology can be abused and misused, there’s nothing inherently bad in any of the P2P technologies.  Just because bank robbers use pens to write hold up notes we didn’t outlaw the pen or pencil…

Originally posted 2009-01-12 12:00:19.

Computer Tid Bits; Malware

Computer viruses, worms, trojans, etc are on the rise… if your computer is connected directly to the internet (or on a public wireless network) you’ll definitely want to have a firewall enabled.  The firewall in Windows XP SP2 (or better) and Vista is reasonably good (so there’s no reason to spend money on one).

Also, you should definitely consider running Windows Defender (free from Microsoft) and a Virus scanner.

Two good free Virus scanners are Avast and AVG.

Avast is extremely thorough, but can put a bit of a load on lower end systems.  AVG isn’t as thorough, but a great deal lighter on CPU.  Also, Avast will require you to register for a key — you can use a throw-away email address (from my experience they don’t seem to SPAM).

Avast

AVG

Originally posted 2008-05-09 18:20:12.

Windows 7 – N

If you’re in the United States it’s unlikely you’ll find a Microsoft® Windows 7 N version on a retail shelf; but if you’re in Europe you might.

The N version of Windows was originally released late in the XP era in order to satisfy an EU order that Microsoft offer it’s customers a version of their operating system without their instant messenger and media technologies.  I believe the sales numbers indicated that no one in the EU really wanted such a version; but it was a good way for the EU to rape Microsoft for a sizable cash settlement and create a pain in the butt for consumers.

If you are forced to buy an N version (it’s the same price as the non N version — but it might be the only thing sitting on the shelf) and you actually want to use Microsoft Media Player (or at least install the Microsoft CODECs) you can do so by downloading a nearly 300MB file (there’s one for 32-bit and one for 64-bit).

And thank the EU for making your life difficult.

Media Feature Pack for Windows 7 N and Windows 7 KN (KB968211)

Originally posted 2009-11-07 01:00:20.

Windows 7 – Install With Multiple Disks

I set out this evening to install Windows 7 Ultimate on one of my “high end” desktops, and like all my desktops it has multiple SATA drives running in AHCI mode (after all, it’s “high end”).

No matter how I setup my drives in the BIOS or with the SATA cables I kept getting the larger (newer) drive as DISK0 in the Windows 7 install and the smaller (older) drive as DISK1.

Finally I started doing some reading on the Internet, and I’m not the only person who’s noticed this behavior.  In fact, some say it’s random.

Based on what I’ve seen and what I’ve read I suspect that Microsoft’s EFI BIOS implementation re-polls [discovery] the drives and ignores what the PC legacy BIOS tells it… and the first drive to respond is DISK0.  In my case the drive I want to be DISK0 is probably predictably slower than the drive I want to be DISK1, so I see consistent results.  However, if the drives are very similar (or identical) you could see either become ready first (a micro-second counts).

This is obviously a bug in Windows 7 (didn’t happen in Vista; but apprently is did happen in Vista SP1 and SP2), and can cause all kinds of problems down the road.

What’s the best way to deal with it?

Open up your case and unplug all but the first drive, do your installation, then power up the drives one-by one (if you have hot-swap capability with SATA you don’t need to power down, if you don’t you will have to power down to plug in each drive in turn).

You can easily change the drive letters in disk manager; and once Windows tattoos the drives they should be fixed in order in disk manager.

If you have a motherboard that uses the Intel chip set you may want to download and install the Intel® Matrix Storage Manager for Windows 7.

If PCs used EFI BIOS (like Macs) this probably wouldn’t be an issue, but since Microsoft uses a soft EFI BIOS to boot, they should have tested this better, and they should have fixed it (there are several people who indicated they reported this behavior during the beta testing).

While Windows 7 might be a nice overhaul of Vista; it’s not without it’s problems, and maybe the whole PC heritage is beginning to be too antiquated to keep updating; perhaps it’s time for a new design.

Originally posted 2009-11-12 01:00:38.

Windows 7 User Account Flaw

I’d say this is just an issue with Windows 7, but it’s actually been present in Windows and Windows Server since Vista…

Plainly put, the organization of information in Windows can become corrupt to the point that Windows is unable to create new users.

Really?

Windows (based on NT) is over a decade old… and to have such a basic flaw seems un-thinkable!

Let’s see, to create a user…

  1. Check to make sure the log-on identifier is unique;
  2. Create a security descriptor;
  3. Create a user home directory;
  4. Copy user default template files to the home directory;
  5. Apply the security descriptor to the user home directory and files; and
  6. Update the user database.

Seems pretty straight forward to me.

And not only is it an essential function of an operating system, but it’s one that we should have every expectation shouldn’t ever fail — and if it does, there should be a procedure to fix it.

Oh, there are procedures to fix it — in fact that are so many procedures you could probably re-install the operating system a hundred times before trying all of them… and there are more than one “Microsoft Fix-It” automated fixes as well, and trust me — your odds of winning the lottery are probably better than one of them actually resolving your issues.

All I can say is that regardless of the potential Windows might have, Microsoft’s actions indicate that it’s not intended to be anything more than a toy operating system — and never was.

Originally posted 2013-09-03 12:00:00.

Dynamic IP Filtering (Black Lists)

There are a number of reasons why you might want to use a dynamic black list of IP addresses to prevent your computer from connecting to or being connect to by users on the Internet who might not have your best interests at heart…

Below are three different dynamic IP filtering solutions for various operating systems; each of them are open source, have easy to use GUIs, and use the same filter list formats (and will download those lists from a URL or load them from a file).

You can read a great deal more about each program and the concepts of IP blocking on the web pages associated with each.

Originally posted 2010-08-17 02:00:55.

SyncMate v3

Eltima has released version 3 of SyncMate; this version includes an app for direct Android synchronization.

I’ll be doing a full review of it in the near future; but for those of you that are extremely happy you might want to consider upgrading.

If you purchased the expert edition you’ll have to pay to upgrade; if you use the free edition you won’t have to pay.  Also not you’ll have to re-establish your synchronization settings, the upgrade doesn’t migrate them.

http://mac.eltima.com/

Originally posted 2011-01-19 02:00:29.