From ATX / NLX to Micro ATX / Low Profile

The first form factor of the early PC clones was the AT style. This gave birth later to what became known as the "Baby AT" which was a common motherboard type for many years along with the AT type power supply. The original AT motherboard measured 305 x 350 mm. The BabyAT boards varied in size, maximum was 220 x 350 mm. In 1995, Intel introduced the ATX style to replace AT/Baby AT.

Earlier low profile PCs used a form called LPX or LPM. These had a riser card to put the peripheral slots on their side. There was no official standard for the design; many PCs in this formfactor were brandnames that used their own proprietary layouts. Occasionally you would see a double sided riser with as many as five slots, however single sided with three was more common. LPX/LPM designs were among the first to integrate many devices such as sound, video and network onto the board since there was rarely enough room in the case for many add-on cards, especially larger ones. NLX was designed by Intel to replace LPX/LPM and was introduced in 1997. However it has essentially disappeared to be replaced by proprietary designs or Low Profile ATX chassis based on micro ATX and other form factors.

Refer to the previous articles showing Compaq low profile desktops to see an example of a proprietary implementation, in this case using a riser card for the slots.

These days low profile clones and some brandnames are produced using MicroATX boards put into a case which has a low profile backplane. A brandname example is the IBM Netvista small form factor desktop PCs in the era of the Celeron 766. A clone case example is the Foxconn DH153 chassis. The case backplane is lower than the standard PCI card and only accepts low profile cards that are fitted with a bracket made in this size. Often, manufacturers produce cards in the low profile form factor and supply brackets for both backplane sizes with the card; however it is necessary to shop around to find them. The Compaq D5S low profile desktop shown in a recent article in this blog was a hybrid; it uses a low profile graphics card in an AGP slot as well as providing two full height PCI slots on a riser. However it's not clear whether the AGP card was a standard low profile design or a proprietary unit.

The picture below shows an ATX board and micro ATX alongside each other.

The layouts are generally similar. The ATX at left has onboard sound while the uATX at right has onboard graphics and network interface as well. The CPUs are a Pentium 166 MMX and Celeron 1000 (100 MHz memory bus) respectively. The chipsets are Intel 430TX and SiS 630 while the models are Asus TX-97X and Asus TUSI-M. The main reduction in size comes from cutting the number of peripheral slots; three is enough these days with onboard integration and USB etc. The other major difference between the boards is the elimination of bus and CPU clock speed and voltage jumpers on the later boards, the settings now being done in the BIOS.

NZ Schools 2007 Software Issues

• eTrust ITM services are not started after installation on Vista. The Realtime agent will report that it cannot access the Realtime service. InoRT, InoRPC and InoTask services are all stopped. Windows Security Center reports that eTrust ITM is out of date. The PC is very slow with a high level of disk activity.
  
• Resolution: From rebooting after installation the PC will be very slow and report these problems but eventually after some minutes the software will start running properly and the PC will be OK.
  

• eTrust Local console (browser based) will not run on a desktop PC. (Connection Refused from some proxies)

• eTrust ITM may not register its license at installation (XP or Vista).


• MOE Vista Business DVD does not boot for installation.
• Workaround: Install another operating system first, insert the DVD, choose Custom Install and configure it to delete the current operating system (for a clean install).
  

%username% with usernames over 20 characters

These days with the increasing tendency to use double-barrelled surnames resulting in a username that could exceed 20 characters in length, it pays to be careful when setting up accounts for such people.

Suppose we have our usernames in the form firstname.lastname and we have a user "abcdef.ghijkl-mnopqrs". This username is 21 characters long including the intermediate period. When we create the account, Windows says their pre-Windows 2000 name will be just the first 20 characters. We might then choose to edit the pre-Windows 2000 name to be "abcdef.ghijkl". But we don't change the long version of the name which becomes the UPN when added to the UPN suffix (i.e. abcdef.ghijkl-mnopqrs@mydomain.xyz). Windows creates an account in Active Directory. If we copied the account from an existing one, Windows might also automatically create a home directory in the same path as the original account which might be something like \\someserver\homes\abcdef.ghijkl

This is OK if you are creating one user at a time and copying them. However if you are creating these users from a script, or creating the home directories separately and setting permissions manually, you need to be aware that references to %username% do refer to the pre-Windows 2000 form of the name (the 20 character one). Folder redirection policy will fail if the policy uses the %username% variable to refer to a home folder whose name does not match the pre-Windows 2000 name.

Windows Live Mail hangs with some feeds; big improvements for IMAP users

I've been testing the Windows Live Mail beta for some weeks at home now. Finally, Microsoft have put an official download page on live.com for it. One of the areas in which I have seen persistent problems is with blog feeds. If the server providing the feed returns invalid or incomplete data, WLM simply hangs, whereas IE7, which acts as the feed agent for WLM, can tell us simply that the feed is invalid, incomplete or missing.

Apart from that issue WLM looks very useful and once the bugs are out of it I will be recommending it for staff use here. A major benefit is the way in which it handles IMAP mail accounts (we use IMAP on our mail server here). All Microsoft mail clients up to this point, including Outlook 2003, store the Sent Items in a local folder on the computer rather than in the Sent Items folder on the IMAP server. This means that the benefits of IMAP, which assume that all the mail remains on the mail server, are lost to a certain extent. WLM has settings to specify IMAP folder names for Sent Items, Junk Mail, Drafts and Deleted Items. The folders on the server will be used for all these if the option is enabled. I've found it works well with an IMAP account I am using.

Always reformat the HDD when replacing Vista with another OS

I have had a frustrating time trying to install Windows XP onto a PC that had previously had Vista installed on it (unactivated). I assumed that because the disk is recognised as NTFS and Windows can delete the existing installation, there would be no problem installing XP without reformatting the disk/partition.

However things are not that simple, and both when using a RIS image, and using a CD installation, I encountered various errors regarding files that could not be copied (which I skipped), then when the automated setup restarted in GUI mode, the setup was halted with a fatal Access Denied error.

Once I got wind of what might be happening and deleted the entire partitition, created a new partition and gave it a full format, RIS based XP setup proceeded normally without any further user input, the way it should normally work. I presume that the Vista setup had left ACLs and other settings on the disk that caused conflicts with XP Setup.

Compaq Personal Computers

In all the years I have been either studying or working in the computer industry, Compaq has been one of my favourite kinds of brand-name PC due to their innovative and imaginative design. Like most brand-names, Compaq don't use bland, boxy generic cases, they have often gone out of their way to create designs that are visually appealing and incorporate clever features that set them apart from the competition as well as making them easy to service and upgrade. Other manufacturers in recent years have begun adopting some of these clever features, but for a long time the generic cases were a long way behind in innovation.

The first four pictures are of a Compaq Evo D5, which is a Pentium IV/1.6 GHz with 256MB of PC-133 SDRAM and a 20GB HDD. The last two pictures are a Compaq Deskpro EN, a Pentium III/1000 with 256 MB of PC-133 SDRAM and a 10 GB HDD.

Compaq EVO D5 front panel view.

Under the hood. The drive bays hinge up to give access to the motherboard underneath. Sound and USB sockets and the power switch are all mounted directly to the board; no need for front panel cabling here. Another nice Compaq feature is that a supply of the cheese head screws needed to mount the drives in the bays is included inside each case. In this picture you can see four black screws sitting in their holes just right of the lower right corner of the CD writer. The drives can be taken right out of the bays without any tools at all.

With the drive bays hinged forward we can see the mainboard. The CPU has, as is commonly the case in brandname PCs, a custom arrangement of fan and ducting to ensure proper airflow for cooling; in this case exhausting through the front panel vents. In the past Compaq has used the power supply cooling fan to good effect as well. This Compaq has a low profile AGP card in its own slot just to the right of the power supply. Two full height PCI slots are in a riser at right rear.
Back panel view of the D5. Even in this day and age it still has two DB-9 serial ports.

The PCI slot riser in the Deskpro EN SFF. This one is for three PCI slots and the card edge plugs into what looks like another PCI slot on the mainboard itself. The riser also carries the case open switch which can be seen lower left.

Deskpro EN SFF power supply hinged up for easy access underneath. Immediately left you can see another clever Compaq feature in some models - the case lock switch. Rather than having something you lock with a padlock, you just make a setting in the Bios to engage this switch and lock the case closed.

Most of the Compaqs I have ever seen are designed to come apart with a minimum of tools. The drive bays use clips and special screws to enable the drives to be removed and exchanged very quickly. The riser comes out as a complete unit - never been that easy in other low profile PCs before. Another important point is that you can use full height cards rather than low profile PCI which most low profile cases require today. The Deskpro EN even had the mainboard mounted on a metal baseplate which could be dropped out of the case very easily. You could have the PC dismantled into its major pieces in about five minutes.

Another Compaq innovation was the convertible desktop/tower case. These are a full height desktop, as they have to be. The drive bay which took three 5 1/4" devices was designed in such a way that devices could be rotated through 90 degrees, making it possible to configure the same case as either a desktop or a tower - simply by removing the devices and reinserting them in the correct orientation.

Overall, Compaq has represented a trend of design innovation in PCs for years and it is hoped that HP will pick up the best aspects of Compaq design and continue that innovation in years to come.

ScribeFire Firefox blogging plugin available

This is my first tryout of ScribeFire, a blogging plugin available for the Firefox open source web browser. Some time ago I mentioned Windows Live Writer, another option for those of us who prefer a proper blogging client as opposed to the limitations of a browser based composition system. ScribeFire is a Firefox plugin but it doesn't require you to open a web page to use it; it is simply making use of the user interface of Firefox to run.

As I currently use Firefox as my default browser both at home and work, due to capabilities for advanced control of those annoying adverts, images and media, ScribeFire would be very convenient and therefore I will be trying it out as much as possible to see what it can do.

One significant improvement over WLW is the ability to justify text. Unfortunately it is still not possible to upload pictures in a Blogspot blog using this plugin so this limits its usefulness to my text-only blogs at present. There are a few little glitches in ScribeFire, one is that changing between it and Blogger's web based composer often causes problems with justification of text.

Champion WD front loading washer/dryer

The last of a long line, this is the comparatively rare Champion WD front loading washer/dryer. Basically this is about all the Champions you can find in public. I know very little about the company operations except that they were called "Radiation Ltd" and were in Dunedin. Champion did a range of everyday ordinary machines, mostly top loaders, dryers and ranges. In the washing department, they ranged through manual, semiautomatic and fully automatic machines. I believe some of the earlier machines were branded "Thor" and may have been license assembled from the UK or US production of that brand (which still trades today in its own right).

The WD front loader was a rare departure for Champion. Once again without access to company information I am unable to state whether this was an indigenous effort or something licensed from overseas. It was also rare for NZ at the time due to the overwhelming dominance of top loading washers, as is the case still today. I know very little about this model except that it was Champion's swansong. They were not very reliable, but some have survived as you still see them for sale from time to time. It was about this time that Sanyo NZ bought out Radiation and after their main business went into liquidation in the mid 1980s, Sanyo sold the remains to Fisher and Paykel.

Eiki SL1 16 mm film projector

In the days before video players, the great multimedia educational resource around the world was, of course, 16 mm sound film. Just about every school in New Zealand had a projector of their own, often installed in a specially fitted out classroom with blackout curtains and a screen. These pictures are of an Eiki projector, which was probably the most common brand in NZ schools although there were others like Bell & Howell etc. When I started at High school, having gone through primary and intermediate watching films in the class, the school decided that we were responsible enough to become student projectionists, and so, with a handful of others, I got a projectionists' certification for Eikis.

The school had three of these as I recall, the oldest required a complete manual threading. The newer models at that time were automatically threaded, push a lever, turn the motor on, feed the film in and it would thread itself. This particular one you see in the pictures is "slot load" meaning the film is just slipped into the slot, then when the knob is turned on the sprockets drop into place and engage the film. You can't manually thread one of these at all whereas an auto threader can always be manually threaded.

Here's a view of the main controls. The big knob top right focuses the lens. The main control knob lower right turns on the motor and lamp. At lower left you have volume and tone controls. The small socket is for a microphone which allowed these units to be used as a small single channel PA with the external speakers, and I did occasionally see one used like this. The small toggle switch appears to be a local modification to select between the built in and external speakers. This particular projector has been fitted with XLR jacks for the speakers rather than the standard 1/4" jack which used switch contacts to cut out the internal speaker when plugged in,

This picture shows the front of the unit with the lamp housing cover removed. The projection lamp is inside the metal cover that says "Caution Hot". Below that can be seen various rollers, the black one to the left is the trailing sprocket. There is a leading sprocket near where the film enters the projector. In this picture also you can see the sound lamp. 16 mm film generally uses an optical soundtrack (although occasionally a magnetic strip is used) which works by shining light through the film onto a photoelectric detector.

At the right you can see the gate. The film moves in the gate by a claw which uses a shutter to block the light off before the film is moved one frame at a time. This conflicts with the continual rotation of the sprockets so the film's movement is buffered by the upper and lower loops which are respectively above and below the gate. It is imperative for the correct operation of the projector to maintain the size of these loops. One of the fun things of the projector was that if tbe bottom loop got too small there was a little arm that was tripped and would rotate one revolution to pull the film through the gate so as to make the lower loop the right size again. This invariably resulted in a jumping picture on the screen.

Inside the guts of the projector with the cover taken off.

A reel of film. Reels were generally five sizes, each being a successive multiple of 400 feet of film. The sizes were A, B, C, D and E - the last was not common. 400 feet of film will last about 12 minutes so the sizes ranged up to 1 hour. Sometimes a film would be on more than one reel. This reel seen here is a C and will hold up to 1200 feet when full.

Films were shipped out from the National Film Library's Christchurch office to schools around the city once a week. At high school they came in on a Tuesday afternoon. We had two projection rooms with their own projectors and in the senior school a third projector was used as needed or as a spare. The projection rooms each had a little room off the back where the projector was and where the projectionists sat and kept an eye on the machine. Once the film was finished it had to be rewound, turning a lever reversed the direction and made it go faster than it would go through the projector. Generally we got extra time out of class to get there a little ahead and thread the projector, then rewind the reels afterwards and lock up the room.

We also learned how to splice film together, which involved cutting the ends off square, scraping off the emulsion, applying a special cement to one end, overlapping the ends and pressing them together in a special tool, although you could get by without it just by lining up the sprocket holes. Films of course went around the country and got damaged. Torn sprocket holes were an example, these would cause the film to jump as the lower loop would usually shrink and trip the reset arm to pull the loop back to size. If this happened too much you had to stop the projector and rethread by pulling more film through from the top to reset the loops back to size. If the film snapped or tore it would have to be spliced which invariably meant cutting out the damaged part, a few frames at least.

Video did not take over until a few years after I left high school. The VCRs then available were very expensive and few titles were available on them. Most high schools would have had perhaps only one or two VCRs in specially equipped rooms due to the cost of them (four figures was common). A far cry from today when there might be one in almost every classroom. But once video did take over then film fell out of vogue, along with the need for the special theaterettes which were in most cases co

Fisher and Paykel 300/400 Series Autowashers

These machines were a licensed UK design. The back panel of most has a plate affixed saying it is an AEI-Gala design. In later years, similar machines were sold in Britain under the Hotpoint brand (possible model numbers are 9600, 9604, 9605). In NZ, the last series of these machines were the 370, 380 and 400 models. The 370 was the budget series model which had, I think, no option switches at all. The 380 was the middle range model with adjustable wash and rinse temperature, water level, spin speed and number of rinses. The 400 was the high end model with the addition of a heating element over the 380. I believe this last series of models were produced from the late 1970s for about five-six years. Our family owned a 380 model for about 10 years, approx 1980-1990. The following photos give some idea of the appearance and layout.

General view of the machine. At left of the control panel is the timer with the option switches in the middle.
Closeup of the control panel, the timer and option switches.

Inside view of the machine with the detergent dispenser/lint filter on top of the agitator. During the wash cycle, water circulates through the machine and is pumped through the water spout seen just below the lid, passing through the "Filter Clean Dispenser" back into the bowl.

The machines had a fairly conventional (for its day) mechanical layout with just one motor driving the pump and gearbox off a V-belt. The pump always turned, circulating the water during wash and rinse cycles, and pumping water out during the spin cycle. When it came time to spin, the bowl was held stationary on the brakes while a slip clutch allowed the motor to turn the pump and drain the water, then the brakes were released and the spin speed gradually built up to 1000 rpm, which for its day was a very high figure compared to other brands. If the slow spin was selected the spin was only allowed to run for the last 30 seconds of the cycle time. The resulting wear in the clutch could become an annual repair item depending on how often the machine was used in this mode.

Apart from normal wear and tear the machines were very reliable. They were also very solid and heavy (88 kg), as with other dynamically balanced designs of the period, a concrete block balanced the motor weight in the chassis. They were sold under the Whiteway, Savaday, Kelvinator and possibly Frigidaire brands, the latter two being licensed by F&P in NZ at the time. So far as I recall the Frigidaire(?) variant of the 380 or 400 model differed in having an additional Gentle Agitate option. On models fitted with the heating element the machine would heat the wash water to 60 degrees C and then start the wash automatically when this was reached. In the warm wash mode the hot inlet valve was opened continuously during the fill while the cold water valve opened and closed cyclically using a simmerstat. The cycle was controlled by setting a knob rather than by actual water temperature.

Although it is now more than 20 years since these machines were built new in NZ, their reliability and longevity has resulted in there being a thriving refurbishment and servicing industry operating around the country and they can still be bought and sold quite commonly. I purchased the machine shown in these pictures approximately three years ago. It is used for about two loads a week and has been very reliable.

NZ Automatic Washer History

Prior to 1984 NZ had import restrictions which meant that washing machines were built in factories around the country. These were often overseas brands assembled locally for domestic demand. There seem to have been three main brands produced:

Norge - locally assembled production of the US brand range. A range of models including twin tubs and top loading automatics. A friend of our family had one of the top loaders, very expensive and rare to see in the early 1970s. As I recall, Norge machines were not particularly innovative or reliable.

Champion - NZ company, their production appears to have included license assembled Thor models from either the UK or US. My grandfather had an older model semi automatic Champion top loader. Most of these throughout a series of models were of a unique suds-saving design that had some sort of internal tank to store the wash water for reuse after the spin cycle. Basically you would wash the load as normal for the wash cycle, then at the end the water would be pumped out, the machine would spin and stop at the end of the cycle. You then would remove the unrinsed washing and store it, then operate the controls to return the sudsy wash water for another load. Then once you had finished doing all the washing you would rinse all the loads one at a time followed by final spin. The storage of water internally meant that the capacity of these machines was less than other machines of similar dimensions.

Champion machines were otherwise unremarkable and of average reliability. In the mid 1980s, Champion's operations were bought out by Sanyo NZ. This was about the time that Champion brought out its front loading design, a combination washer and dryer. They were very unreliable and only in production a year or two, but you still see them around in the second hand places occasionally. That was the end of the road for Champion; Sanyo sold their operations to Fisher and Paykel.

Fisher and Paykel - Started selling a local version of a British designed automatic washing machine (licensed from AEI-Gala as the back panel says). These machines must have been in production from the 1960s I should think. In 1985 the first electronic machine the ECS was released. A few years later this was updated to the Smartdrive design using much the same basic layout except that a direct drive motor is now used. (There are going to be several articles on F&P autowashers which will cover these in more detail)

Other brands - there were various Australian automatic brands as well as a few NZ ones. You do see the odd Bendix frontloader around the place as well as Hoovers, Simpsons etc. Many of the Australian machines of the 7os and 80s had suds-save capabilities providing that the water could be stored outside the machine (in the tub for example) and pumped back in as required. Hoovermatic twintubs were quite popular in NZ. There were endless models of wringer machines produced in NZ - the F&P Whiteway brand was just one, Beatty, Pallo, Airco are others that come to mind off the top of my head. Atlas was a brand of automatic machine that was only in production a short time so I would think they are fairly rare.

Maxtor 2F020 HDD

This is another interesting HDD (20 GB), early 2000s. It's branded a "Fireball" and thus, possibly, is a relabelled Quantum design. What is interesting about this one is that it has only one head. This is very rare in HDDs because normally you can use both sides of the platter to increase your capacity. The head in this case sits right under the platter which has no head on top. When the platter is put in, the head is hidden underneath.

PC History: Quantum Bigfoot HDD

The Bigfoot was a rare example of a modern IDE drive produced in the 5 1/4" form factor. These were a budget drive often found in low end PCs of the time. The capacity started at 1.2 GB and went all the way up to 19.2 GB. This example is 4.3 GB and was installed in my first PC which I bought in 1997. Bigfoot drives were generally slower than comparable models of the era, in part due to the slow 3600 rpm spin speed - 4500 or 5400 rpm drives were commonly available at the time. No other manufacturer since has been interested in producing drives of this form factor. So the Bigfoot occupies its own little niche of PC history.

Other Technical Topics

As things have been a bit slow lately and as I can't be bothered setting up yet another blog, from time to time this blog will divert onto technical but non-computer topics of interest. You may also see technical articles on design aspects of certain types of computer hardware. Both of these areas are different from the main function that this blog was originally set up for - the day to day operations of a school computing environment.

So, the first articles will appear shortly

Using Loopback GPOs

This is one subject I never did quite get the hang of when I studied GPOs in MOC 2274/2279. The MS documentation for loopback policy is a little confusing.

The normal way that GPOs are applied is that the computer configuration part of the GPO is applied to computer accounts, and the user configuration part of the GPO is applied to user accounts. Say the computer is called ABC and the user is called xyz. At first startup, the computer configuration GPO is applied to ABC. When user xyz logs on to ABC, the user configuration GPO is applied for that user account.

Loopback is different in that it permits a user GPO to be applied to a specific computer depending on the OU in which that computer appears. Normally, the only GPO you can specify for a computer account is the computer configuration. The user config GPO is determined by the OU that the user account is stored in. When loopback is enabled, the user config GPO is determined by the computer account OU instead. This enables the normal user settings that would apply for that particular computer or group of computers to be overridden.

An example in our network is that for pupil users, we have their user GPO set up to redirect their Start Menu to the All Users Desktop. This gives them a great big start menu with all the shortcuts in one long list, no subfolders. First thing I tried to make a nicer start menu was to put the start menu into the mandatory profile. The problem was that on a couple of PCs this didn't work out for some reason. Maybe I missed something. Anyhow, the next idea for this group of PCs is to redirect the user's start menu to the All Users start menu. This worked. However this is a different configuration from other pupils machines. So, I created a new OU, linked a new GPO to it, set Loopback Policy to Enabled (Merge) and set just one setting: redirect the Start menu to C:\Documents and Settings\All Users\Start Menu. After configuring the Start Menu, it was all go. Only the PCs that are in this OU will have this configuration applied, because only they have the reconfigured All Users start menu.

The drawback of loopback policy like this is that every user who logs onto a PC gets the same user settings. In this case everyone gets the limited Start menu, even if they are an administrator. Only the local administrator account can get full access to the PC. In this case, I'll only use loopback until such time as every pupil PC in the school is configured with the new start menu settings, and then apply them to pupil users globally.

Why, incidentally, would it be necessary to redirect the start menu? We need to restrict what appears on the Start menu for pupils. Partly this is for security, limiting the ability to tamper with settings, and partly meeting the AUP. Windows XP has changed from previous versions of Windows in terms of the policy settings that control access to the start menu. The options were reduced somewhat. MS seems to want to discourage limiting the Start menu, but I doubt that many sysadmins would agree with them.

MOE creates SMS user groups

The Ministry of Education recently set up a number of egroups for the different SMSs (Student Management Systems) that they accredited for use in NZ. In addition there is another egroup for the data sharing approval framework. MOE has also announced there are not going to be any more accreditation rounds for SMSs. Instead there will be an annual process based on data sharing approval for producing an annual checkup of SMS vendors.

Data Sharing in general is an initiative that includes the possibility of schools being able to transfer SMS data rather than paper records when pupils move between schools. To get the full benefit of such a system, the SMS should be used to record as much data as possible, including all assessment results. Other possible applications for data sharing might include exchanging data between an SMS and a library system, or a Learning Management System.

Over time, the use of an LMS could replace the need for paper reporting. The LMS would give parents the ability to log in and obtain assessment results at any time. Since the SMS could store data from all assessment results rather than just a summary, a more detailed picture of assessment progress can be obtained. When the pupil changes to a new school, these more detailed records can be transferred fully giving the school a good picture of the new entrant as well.

Another advantage an LMS has is where assessment data comes from more than one school. Suppose that a pupil is enrolled at School A but takes several classes a week at School B which are not available at School A. In this case School B can also enter assessment data into the LMS which is available immediately rather than School A having to gather that data from School B and enter it themselves, saving on time and resources.

In the case of RM Integris, I understand an LMS is being promoted with the G2 web based product currently in development. It is unclear when NZ Integris users are likely to see the G2 product become available for use.

DNSAPI 11163 errors

In event logs for some of your desktops you might see this message:

The system failed to register host (A) resource records (RRs) for network adapter
with settings: [Followed by network adapter information]

The reason the system could not register these RRs was because the DNS server failed the update request...

What you can expect to see happening from the user's point of view varies. In this case, there appeared to be a normal user logon process taking place. However I found that I could not log remotely into this particular computer, the most likely cause for this being that the system's local IP address was different from the one that the DNS server listed in its forward lookup zone for the LAN domain. When I replaced the name of the computer with the IP address shown in the event log entry, remote login was able to take place normally.

There are a number of reasons why this error can occur. In this case, I checked out the configuration of the DNS servers, and found that one of them did not have a reverse lookup zone covering the entire subnet. Our original network had a 24 bit subnet mask. To make DHCP redundant I chose to expand the subnet to 512 addresses instead of 256 (with each DHCP server managing its own half of the address pool) and this meant a change to a 23 bit subnet mask. But in one of the DNS servers the reverse lookup zones only covered the original 256 address subnet. As soon as I added another reverse lookup zone for the other half of the subnet and restarted about 30 machines for testing, the A records for all those machines appeared in the new reverse lookup zone almost immediately.

The other DNS server already had this zone present so there was not a problem with it. The two DNS servers are Active Directory replicating, but I take it that zone changes on one are not automatically replicated to the other. Not that I have assumed that in the past; somehow the change in zone configuration was overlooked. The computers are no longer generating these DNSApi events in their event logs. Since we have had problems with some machines randomly losing network connections I am keen to run down all issues like these, to see if any of them are responsible for these types of problems that have been occurring.

Several other possible causes for this error include:

1. Cloning machines (identical SIDs)
2. Unknown or obsolete SID
3. Local RTC too far out
4. Single label domain name

Although many of our desktops were originally cloned with Ghost we ran Ghostwalker on them to give them each a new SID at the time. In addition the sample desktop in this case had recently been reimaged using RIPREP which gives it a unique SID.

Vista not offered on TELA laptops yet

Rumour has it that XP OEM licenses will be phased out in January. Some TELA laptop vendors are certified for Vista, but these models aren't yet being offered to schools for lease. We have some laptops coming up for renewal in September, and I don't think Vista will be available before then. It may be available by the time more renewals come up in November.

On the other hand, we have yet to receive the Vista DVDs from Datacom on the Microsoft Schools' program - we can only test on unactivated evaluation installations of Vista until we get the DVD. Since it has only just been released, the MOE is probably right in holding back on laptop deployment until it is more widely available in schools, and perhaps more stable.

Resolving IP address conflicts

One of the most annoying things you can ever see on a PC is the duplicate IP address warning dialog. If you dismiss this, it pops up again a couple of seconds later and will just keep on doing that until you give up in disgust.

There isn't much documentation to be found on the Internet, and I'll skip over the most likely cause - that someone has plugged a laptop configured with a static IP address into your DHCP-configured network.

Our case has been much more difficult to track down. We have DHCP redundancy achieved by having two DHCP/DNS servers (which are also our two Windows DCs) on our network. The standard way of getting redundant DHCP is to split your subnet in half and allow each server to assign addresses over its exclusive half of the subnet. Naturally you exclude the opposite server's address range from being issuable.

Windows clients can deal satisfactorily with the subtleties of Windows DHCP, but you need to watch out for things like PXE and similar network boot systems which don't follow the conventions because Windows isn't running. I inspected an event log for a system that had recently experienced a large number of conflicts and found that the conflicting address was listed together with the MAC address of the conflicting system, but there was no record of that system in the DHCP server's current lease pool. However, the same server had the conflicting system listed in its ARP table. The MAC address turned out to be the other DC which, being an Intel server, has a Lan Bios console that runs during the boot process and seeks an IP address from a DHCP server (similar to a PXE client). Evidently that address, which is of no effect once Windows Server is running, is still recorded and causes the conflict error messages to appear even though the address is no longer in use.

I'm hoping this is just a matter of reconfiguring the DHCP servers. I wouldn't want to have to reserve addresses for every single PC in case we use PXE, let alone this one server.

2nd NZ SchoolTech Conference Coming Up

SchoolTech 07 is coming up in July in Auckland, Wellington and Christchurch. As with the inaugural conference last year this promises to be a showcase of IT technologies that are of interest to the school sector.

Although the range of keynote speakers and topics is new, attendees will see little difference in the vendors' stalls and seminars, and some are only offered in Auckland.

Notably absent from these conferences in the past two years have been major vendors like Microsoft and Novell. Having a larger range of vendors involved would make this conference more appealing, whereas at this time the value of the conference is restricted by this limitation. I probably will be attending but there would have to be much more happening in future years to get me back there.

* UPDATE * Tuanz's website now shows that the Christchurch and Wellington events have been cancelled. I was already half thinking of changing my mind and not going, because there isn't that much that is new except for the keynotes. If these events are going to be successful in future years there is going to have to be much more variety in the vendors and their seminars. Nearly all of them are the same as last year. Why can't they get Microsoft, Novell, Integris etc along to these events?