Category: Technical

Quotas Revisited for Windows XP

The other day I provided a post about quotas that contained a simple three step process for turning quota monitoring on and logging quota events, without actually enforcing the quota. It turns out that the process works just fine with Vista and Windows 7, but it doesn’t quite work with Windows XP. Microsoft made a fix between operating systems and didn’t mention the change to anyone. Of course, this is an old story with Microsoft. You have to watch carefully because you might miss a fix and find that your perfectly functioning batch file or script suddenly stops working.

It turns out that Windows XP does things a little differently. When you execute the FSUtil Quota Track C: command, you get the expected result; tracking is enabled. The next step is to turn on exception logging using the WMIC QuotaSetting Where Caption=”C:” Set ExceededNotification=True command, which also works as expected. However, when you execute the WMIC QuotaSetting Where Caption=”C:” Set WarningExceededNotification=True command to turn on warning logging, suddenly, the exception logging is turned off. Likewise, if you were to reverse the order of the two WMIC commands, you’d find that warning logging is turned off.

Fortunately, there is a fix to this problem and it’s a very odd fix indeed. In order to enable tracking and turn on both levels of logging, you need to follow this order in Windows XP:

  1. FSUtil Quota Track C:
  2. WMIC QuotaSetting Where Caption=”C:” Set ExceededNotification=True
  3. WMIC QuotaSetting Where Caption=”C:” Set ExceededNotification=True

That’s right, you issue the exception logging command twice and you’ll find that both logging check boxes are checked. Microsoft fixed this particular error between Windows XP and Vista, but I can’t find any source that tells me about the fix. If you find one, feel free to contact me at [email protected].

A Potential Eye Gaze System Replacement

I view the computer as a great equalizer. People who have special needs can rely on a computer to give them access to the world at large and make them productive citizens. In fact, I’m often amazed at what a computer can do in the right hands. People who used to be locked away in institutions are now living independently with help from their computer. That’s why I read a ComputerWorld article today, “Look, no hands! G.tec uses brain interface to tweet” with great interest. I don’t think this system could replace eye gaze systems for those who need them today, but the system holds great potential as an eye gaze system replacement in the future.

So, just what is an eye gaze system? Imagine you have two cameras mounted on either side of a monitor. The cameras are focused on someone’s eye position. As the person moves their eyes to look at a letter on a card above the monitor, the cameras record the position and use the information to tell the computer what letter to type. Of course, eye gaze systems can be used for more than simply typing letters. Some of these systems are extremely complex and can record the viewer’s gaze at any position on the monitor. Check out the LC Technologies setup as a modern example of what an eye gaze system can do.

The problem with eye gaze systems is that they can be slow, error prone, and tiring to use. Unless the system is properly calibrated, using eye gaze to interact with a computer can become frustrating and time consuming. This brain computer interface is exciting because it promises higher speed (0.9 seconds once trained) and the potential for errors is greatly reduced. However, this system is still in its infancy, so eye gaze systems will continue to be important for people with special needs well into the future. You can read more about accessibility topics in my book, “Accessibility for Everybody: Understanding the Section 508 Accessibility Requirements.” Let me know what you think of this new technology at [email protected].

 

FSUtil and Quotas

There is more than a little confusion about the use of FSUtil with quotas. For one thing, precisely why would someone use the FSUtil Quota Track command when it doesn’t enforce the quotas you set? I’m sure Microsoft has some scenario in mind for just tracking and not enforcing the quotas. I did talk with one of my administrator friends. She uses just the tracking option at her company. The reasoning is that she can then talk with the user when the user goes over a limit. In this particular organization, it’s bad form to limit the user’s access to the hard drive when in the midst of an important procedure (as it might have dire consequences). She says that she does see the event log entries when someone goes over their quota. So, that’s one potential scenario—you have an administrator that has to work with the users to maintain the hard drive but isn’t allowed to enforce those limits directly because doing so could impede work.

Of course, one of the problems with the tracking feature is that it doesn’t automatically set logging. In order to configure drive C on your system to track user activities and log them in the event, you must initially configure the drive using these three commands.

  1. FSUtil Quota Track C:
  2. WMIC QuotaSetting Where Caption=”C:” Set ExceededNotification=True
  3. WMIC QuotaSetting Where Caption=”C:” Set WarningExceededNotification=True

The two WMIC commands set the two logging options for you. What these commands do is set the quota exceeded and quota warning flags for drive C. After you issue these three commands, the Quota Settings dialog box will look like this:

Quota1

You can now add quotas using the FSUtil Quota Modify command as described in page 89 of my book, “Windows Command Line Administration: Instant Reference.” Generally speaking, you can add an overall quota for the entire drive or individual quotas for each person. The overall quota affects everyone who doesn’t have a specific individual quota.

OK, now you’ve configured the C drive to provide quota information in the form of event log entries. So, you create a test case to make sure everything works and that’s when you figure out that you can’t see any entries in the event log. In addition, it appears that the FSUtil Quota Violations command doesn’t work either. Well, that’s a little disappointing.

The problem is a lot simpler to correct than you might initially think. Microsoft hides the information you need in the Knowledge Base article at http://support.microsoft.com/kb/228812. The short story is that NTFS only scans the drive once an hour for violations, so you’ll have to wait a while to see any test violations. Of course, you might not have all day to wait around for NTFS to get around to scanning the drive. So, you can use the FSUtil Behavior Set QuotaNotify 60 command to set NTFS to scan the drive once a minute. In order to get this command to work, however, you must reboot the system. It seems that NTFS also loads its settings once during each boot cycle and then ignores the registry settings thereafter.

Once NTFS starts scanning the drive at a reasonable interval, you’ll begin seeing entries in the System event log. In addition, you can use the FSUtil Quota Violations command to look for violations as shown here:

Quota2

At this point, you’re ready to go. Your system is setup to monitor quotas in a critical environment, but not to enforce the quotas (thus preventing people from completing tasks). I’ve had at least one person tell me that the FSUtil Quota Violations command tends not to work if the System event log gets too full; I’d like to find out whether other people are having the same problem. Let me know how you use quotas on your system at [email protected].

Regular Expressions with FindStr

Regular expressions are a powerful feature of the FindStr utility. However, they can also prove frustrating to use in some cases because the documentation Microsoft provides is lacking in good examples and difficult to follow. You can see some usage instructions for FindStr starting on page 82 of the Windows Command-Line Administration Instant Reference .

A reader recently commented that there is a problem with the dollar sign ($) regular expression. It must actually appear after the search term to be useful. Of course, the problem is creating a test file to sufficiently check the use of the regular expressions, so I came up with this test file:

TestFile

Now, let’s perform some tests with it.  Here is the result of some tests
that I performed using this test file and FindStr regular expressions:

TestResults

The first test case shows what happens when you try
the command on page 82 of the book.  It appears to work, but you’ll see
in a moment that it actually doesn’t.  Let’s take the two parts of the
regular expression apart.  Using FindStr “^Hello” *.TXT seems to work just fine.  However, the command FindStr “$World” *.TXT doesn’t produce any output.
Only when the $ appears after World does the command produce an
output.  Consequently, page 82 should show the rather counterintuitive
command, FindStr “^Hello World$” *.TXT to produce the correct output.

It’s also important to be careful about making generalizations when
using FindStr. For example, when working with the test file originally
shown in this example, the FindStr /B /C:”Hello World” *.TXT command produces the same output as FindStr “^Hello” *.TXT as shown here:

TestResults2

If you change the test file like this though:

TestFile2

you’ll see these results:

TestResults3

As you can see, you must exercise care when using FindStr to obtain the
desired results.  What other odd things have you noticed when using
regular expressions with FindStr?  Add a comment here or write me at [email protected] to let me know.