Windows 2008/R2

Good afternoon.  I ran into an interesting issue this afternoon I wanted to share.  I had a customer that was receiving the following error:

“The volume cannot be extended because the number of clusters will exceed the maximum number of clusters supported by the filesystem.”

He encountered the error when trying to extend a volume.  The volume was 20TB (Terabytes) and he was trying to add another 19TB for a total of 39TB.  After some research I found, based on his setup, that the maximum volume size was 32.75TB.  We extended the volume to that size and we were done.

I figured someone might find it useful if I l go over the process of determining the maximum size for a volume.  There are a couple pieces of key information that are required.  The first is the maximum number of clusters in a NTFS volume.  This is 2^32 -1 clusters, or roughly 4 billion.  The second piece of information we need is the bytes per cluster.  To get this information, run the following command: fsutil fsinfo ntfsinfo x:
Replace the x: with the actual drive letter.  Below is output from the command.  In this example we see that we are using 4096 bytes per cluster or 4K for short.

Now that we have both pieces of information we just need to do some simple math to find the maximum volume size.  Multiply the maximum maximum number of clusters by the cluster size.  Taking the example above, that would be 4,294,967,295 * 4096 = 17,592,186,040,320 bytes.  To convert this to megabytes, divide the number by 1,048,576 (1024*1024).  In this example we get 16,777,215 Megabytes.

To make this even easier, here is a handy table:

Cluster size	NTFS Max Size
512 bytes	2,199,023,255,040 (2TB)
1024 bytes	4,398,046,510,080 (4TB)
2048 bytes	8,796,093,020,160 (8TB)
4096 bytes	17,592,186,040,320 (16TB)
8192 bytes	35,184,372,080,640 (32TB)
16384 bytes	70,368,744,161,280 (64TB)
32768 bytes	140,737,488,322,560 (128TB)
65536 bytes	281,474,976,654,120 (256TB)

I hope you enjoyed this article.  If you have any suggestions or comments please leave them below.

Today I wanted to mix it up a little.  I want to talk a little about debugging, more specifically about using driver verifier.  If you have seen a Windows bug check, aka the blue screen of death, then you have probably seen a DRIVER_IRQL_NOT_LESS_OR_EQUAL.  This particular bug check has two codes associated with it; 0x0000000A and 0x000000D1.  In the majority of cases, this bug check is caused by a 3rd party driver that is misbehaving.  Most of the time the cause can be identified by debugging the kernel memory dump.  Sometimes however the problematic driver is paged out and is no longer present in the memory dump.  In this case we can use driver verifier to catch this misbehaving driver and force a bug check to happen before the driver is paged out.  The rest of this article will discuss how to enable driver verifier for this scenario.

1. Click Start, or in Windows 2012 and higher right-click Start, and choose Run.  Type in verifier and click OK.
2. From the select a task options, select “Create custom settings (for code developers)” and click Next.
   
3. From the select individual settings from this full list, tick the check box for Special pool and click Next.
   
4. From the select what drivers to verify options, select “Select driver names from a list” and click Next.
   
5. Sort the driver list by provider.  Tick the check box for all drivers that are not provided by Microsoft, and click Finish.  We do this so that we can monitor all 3rd party drivers.
   
6. Reboot the server.

After the server is rebooted all 3rd party drivers will be monitored.  If one of them should misbehave, driver verifier will force the system to bug check.  It should then be fairly simple to find the problem driver in the memory dump.

If you have any suggestions for this article, please leave a comment below.

I ran across a great blog article on setting up a split DNS (Domain Name System) zone this morning.   It got me to thinking though, can I do this in PowerShell?  The answer is yes.  And it is quicker than using the DNS management console.  Change the zone name and IP address to match the name and server IP respectively.

1. Add-DnsServerPrimaryZone <test.mydomain.com> -ReplicationScope “Forest”
2. Add-DnsServerResourceRecord -A -Name “.” -ZoneName <test.mydomain.com> -IPv4Address <99.99.99.99>

 

If you have a way of doing this command in one line I want to hear about it.  Post it in the comments below.

I ran across this issue today with a customer and it took quite a bit of digging to find a solution.  Here is a screenshot of the error:

In digging around I found there is a utility to address this issue, but I am cheap and don’t want to pay for something if I can find an alternate solution.  Without further ado, here is how you fix it.

To delete a file:

1. Open an administrative command prompt.
2. Run the following command: del “\\?\X:My Directory\Bad File.ext”  (Replace everything after \\?\ with the actual path to the problem file.)

To delete a folder/directory:

1. Open an administrative command prompt.
2. Run the following command: rd /s “\\?\X:My Directory\Bad Directory”  (Replace everything after \\?\ with the actual path to the problem directory.)

 

Where is that easy button?

 

 

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Thanks to  Rayza73 who posted this on the Microsoft forums.