The bootfile is too small to support persistent snapshots

Posted on by Glenn

Good afternoon. It has been too long since I last posted. Today I found a solution to a problem I have seen several times and I wanted to share it.

I had a customer that was experiencing backup issues with a new load of Windows. When trying to backup the server in Windows Serer Backup the backup would always fail with the error “Windows Backup failed to create the shared protection point on the …”. An important point to note is the error would always occur during the VSS snapshot phase of the backup.

Below is the resulting Application event log with the key event highlighted.

At this point it is probably helpful to get a high level overview of how Windows Server Backup and VSS work. When Windows Server Backup starts a backup one of the first steps is to call VSS to take a snapshot. When the backup destination is local disk, the request is for both the backup destination and the backup source. This is so that Windows Server Backup can compare the blocks in both to perform an incremental backup. This means that a failure to snap the source or destination can cause the backup to fail.

I have seen this issue a handful of times and the consensus was the backup drive was causing the problem. While this can be the case, today I learned how to pinpoint which volume is actually causing this error with the event log. The key to determining this is the volume GUID ( Globally Unique Identifier) specified in the description of the event. This is the volume that cannot be snapped by VSS and is causing the backup to fail.

So how do you take the GUID and get the drive letter? This is the easiest part. Simply open an admin cmd window and run the command “mountvol”. At the end of the output all volumes with GUIDs and drive letters will be listed. In our case it was the D:\ drive that contained user data. We ran a test backup excluding the D:\ drive and it completed with no errors.

How do I fix the volume, so it will backup? Obviously we will not want to exclude a volume from the backup. There are two methods to repair this issue. First a chkdsk /f can be run to attempt and repair the volume. If that fails though, then you are likely looking at a bit of work to recreate the volume. Here is the process:

  1. Backup the data with robocopy or another file level backup utility. For robocopy an example command: robocopy <source> <destination> /MIR /XJ /W:5 /R:3 /LOG+:c:\robolog.txt
  2. Run diskpart and “clean” the disk. To do this run diskpart at an admin cmd, select the problem disk, then run the clean command.
  3. Recreate the volume
  4. Restore the data with robocopy or whatever file level backup utility used previously.

I hope you have found this post informative. If you have another way to solve this problem I would love to hear about it in the comments.

User profile corruption for Windows service accounts

Posted on by Glenn

Good morning. It has been a while since I posted, so I figured it was time for another article. I ran across an interesting issue this morning that I figured I would share. I had a customer that had recently experienced some file system corruption on the C: drive. Luckily chkdsk was able to correct the issue, but there was an issue that cropped up after running it. My customer was seeing an error in the Windows system log coming up frequently. The error was a 7005 with a source of Server Control Manager. The description was his concern though.
“The LoadUserProfile call failed with the following error:
The configuration registry database is corrupt.”

I did some research on this error and it is caused by a corrupt user profile. I figured it was probably a service user account as we had several services starting within seconds of each occurrence. Through a process of elimination I discovered that starting any service using the Network Service as the logon service caused the error.

So now I knew which account was causing the error, but how do you recreate the user profile for the Network Service user? I first checked the c:\users folder and the profile is not there. It is also not in the user profiles list in the system properties. I checked the registry as it has a list of all users with profile locations.
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList

Bingo!

The Network Service profile is located in C:\Windows\ServiceProfiles\NetworkService. I renamed the profile in the registry (S-1-5-20) to S-1-5-20.old and the NetworkService folder to NetworkService.old.

I then started a service that used the Network Service account, and success. The registry key was recreated, as was the folder, and we received no errors in the event log.

On a side note the above process will also work for the Local Service account. Just rename the appropriate registry key and folder.

I hope you found this article informative. If you have anything to add or would like to suggest an edit, please do so in the comments below.

Performing a bare metal restore with Windows

Posted on by Glenn

Good morning.  I had a question today on what to do if the hard drives are not detected when performing a bare metal restore.  Loading the driver is pretty straightforward, but I could not find a good guide on the whole process, so I figured it was time to put one together.  Below I will outline with screenshots the process to do a bare metal restore.  The screenshots will be from Windows Server 2016, but the process is the same for all currently supported versions of Windows.

  1. We start by booting to the Windows media.  After selecting the language, you have two options; Install now or Repair your computer.  Choose Repair your computer.
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  2. The next screen may give you more or fewer options.  Choose Troubleshoot.
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  3. From the Advanced options screen, choose System Image Recovery.
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  4. If given the option for a target operating system, choose the one applicable to you.
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  5. On the following screen, you will have two options; Use the latest image or select a system image.  If you want to restore the latest backup, then you simply need to click next.  If however you want to restore an earlier backup, choose the option to select a system image.  This guide will continue with the second option.
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  6. If you have only one backup drive, then only one line item will show.  A line for each backup drive will be displayed on this screen.  Choose the backup drive to restore from and click Next.
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  7. On this screen all the available backups are displayed to restore from.  Select the preferred backup to restore and click Next.
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  8. This screen provides three important options.  The first is to format and repartition the disks.  Select this option to completely wipe the drive being restored to.  It is possible to exclude data drives from this by clicking the exclude drives button and checking the drive to exclude.  The second option will only restore the system drives.  Keep in mind though, if the page file was moved a data drive, that drive is now considered a system drive and has to be part of the restore.  The last option is to install drivers.  Do this if the drives being restored to are not detected by the restore wizard.  Once all desired options are selected, click Next.
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  9. This screen is a summary of the restore.  Click Finish to start the restore process.
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After clicking yes on the prompt, the rest of the process is automated.  The server will be restored and automatically boot back into the restored Windows OS.

I hope you found this post informative.  If you have anything to add or suggest, please do so in the comments below.

Error 1202 from DFSR

Posted on by Glenn

I ran across an interesting issue I wanted to share.  I had a customer that recently had a migration performed.  Previously he was running SBS (Small Business Server) 2011 and is now running Windows Server Essentials 2016.  After demoting and removing the SBS 2011 server, he started receiving the following error on every boot.

1202 DFSR

The error is quickly followed by an informational message indicating that DFSR (Domain File System Replication) successfully connected to a domain controller.

Based on my previous experience with similar issues I posited that the problem was due to the DFSR service starting before either the network stack was fully initialized or before the DNS (Domain Name System) service was running.

I explained that based on the behavior this could safely be ignored.  This did not go over very well as the error also shows up in the Windows Essentials health report.  This brings us to the solution.  And this solution will work for just about any service that needs a little more time at boot.  We set the startup type for the DFSR service to Automatic (Delayed Start).  We restarted the server and this eliminated the 1202 error.

I hope that you found this article informative.  If you have anything to add, please feel free to leave a comment below.

The diskshadow command, a hidden gem

Posted on by Glenn

Good morning.  In case you haven’t guessed it already I typically write these posts in the morning.  As I write this now it is 6:30AM.  Today I wanted to share a command line utility I just recently discovered.  It has been part of Windows for quite some time though.  At least since Windows Server 2008.  The utility is called diskshadow.  This utility allows direct interaction with VSS (Volume Shadow Copy Service).  You can find the Microsoft technet article here.  In this article I will go over how I used it to troubleshoot a recent issue with VSS.

I was recently troubleshooting a VSS where the snapshot was failing on release.  As is typical, my customer was using a 3rd party backup software.  I wanted to test outside of the backup software, so we installed the Windows Server Backup feature and tried that.  Unfortunately the symptoms were identical.  After quite a bit of digging I ran across the diskshadow utility.  With that utility I received a different error which led me down the path of discovering the problem.  It turned out that the backup software’s filter driver was stepping on VSS and causing the failure.  After removing the backup software, VSS worked without issue.

So how is the diskshadow command used?  It can be used to create a snapshot, mount an existing snapshot, restore a snapshot and several other things.  Below I will cover the commands to take a VSS snapshot, as that is the functionality I find most useful.  To take a snapshot of the C: drive and test the majority of the VSS writers there are just 3 commands that need to be run.

  1. diskshadow (This starts the command and puts you at a diskshadow prompt.  This is similar to ntdsutil and nslookup.)
  2. add volume c: (This adds the C: drive to the snapshot.  You could substitute another drive letter if you want to test a specific writer.  The command can also be repeated with other drive letters to include them in the snapshot.)
  3. create (This starts the snapshot process with VSS.  It is important to note that the create command by itself will create a non-persistent snapshot.  That is the snapshot will be removed on exit from the diskshadow utility.  A persistent snapshot can be created with additional parameters.)

This utility is considerably faster when troubleshooting VSS, taking only about 1-2 minutes to take a snapshot or fail.  It also removes the requirement for a USB drive to temporarily store a backup.  For these reasons I will be using whenever troubleshooting VSS in the future.

I hope you found this article informative.  If you have anything to add or just want to leave a comment, please do so below.

 

The Network Location Awareness service

Posted on by Glenn

Good morning.  I wanted to share an issue I see on a regular basis.  This has to do with the NLA (Network Location Awareness) service.  For those that are not aware of this service it is responsible for determining the type and safety of the network(s) the computer is connected to.  There are 3 network classifications that are used.

  • Public – The NLA determines the computer is directly connected to the Internet or is on an unsafe network.  This is also the default profile assigned to a network adapter until one of the other profiles can be determined.
  • Private – The NLA determines the computer is isolated from the Internet by a NAT (Network Address Translation) device or router.
  • Domain – The NLA determines that the computer is connected to a domain.  It does this by attempting to contact a domain controller.  More specifically it performs a DNS (Domain Name System) query for a SRV (Service) record.  It will then make a connection to the domain controller.  If this is all successful, the domain profile is set.

So what is the purpose of the NLA and setting a network profile?  The primary purpose is for the Windows firewall.  Other applications and services can also access this data though.

Now that the NLA service is sufficiently explained, on to the common issue with it.  The NLA service by default is set to Automatic for its startup type.  Normally this works fine and the NLA properly detects the network.  There are some situations though where the service fails to set the profile correctly on startup.  I typically see this on domain controllers in a domain with just one domain controller.  This means that the network stack and DNS server service have to fully initialize and start before the NLA queries the network.  If they do not then the NLA is not able to contact a domain controller and assumes the computer is connected to a private or public network.

Regardless of the reason why the NLA is failing at startup the solution is fairly simple.  I have seen a 100% fix rate with simply setting the service startup type to Automatic (Delayed Start).  Doing this forces the NLA service to wait until all Automatic services have started, giving DNS enough time to start.  I have seen this little trick work with other services when they are having trouble at startup.

I hope you found this article informative.  If I missed anything or you just want to comment, please feel free to do so below.

An error has occurred 0x8007….

Posted on by Glenn

This article is for those that don’t know that 0x80070002 is “The system cannot find the file specified.” or that 0x80070020 is “The process cannot access the file because it is being used by another process”.  It seems impossible to memorize all the error codes in Windows and what they mean.  Thankfully there is no need to do this, as there is a utility built into Windows to decode them.

To find out what an error code means launch a command window and run this command slui 0x2a <error code>.  For instance slui 0x2a 0x80070002.  You will get a popup similar to the following:

slui 0x2a

You will need to Show details.  The description is the error code text.

I hope you found this article informative.  If you have anything to add please do so in the comments below.

The case of the missing domain controller…

Posted on by Glenn

I wanted to talk about an issue today that I see with a great deal of regularity.  Statically setting an external or public DNS (Domain Name System) server in the DNS client settings of a machine that is joined to an Active Directory domain.

external-dns-server

In the above picture we have the Active Directory domain controller as the Preferred DNS server.  However we also have one of the Google public DNS servers as the Alternate DNS server.  At first look, it appears this might be a good idea.  If the Active Directory domain controller goes down, this PC can still resolve names on the Internet. However there is a significant disadvantage to setting up the DNS client in this way.  To understand this disadvantage, we must first understand how the DNS name resolution process works in Windows.

When a Windows system, either client or server, needs to resolve a name it goes through the following process.*

  1. The client checks to see if the name queried is its own.
  2. The client queries the DNS client resolver cache.  Any entries from the hosts file are preloaded to the resolver cache.
  3. Domain Name System (DNS) servers are queried.
  4. If the name is still not resolved, the NetBIOS name resolution sequence is used.

*I have omitted WINS from the process as it is rarely used anymore.

Let’s dive a little deeper into bullet point two.  There are two important takeaways for the DNS client cache.  The first is the time limit a record or lack thereof is cached.  This is typically referred to as TTL (Time To Live).  A positive answer is cached for its TTL or 24 hours whichever is less.  A negative response, that is when the record does not exist or cannot be found, is cached for 5 minutes.  The second takeaway is that clearing the cache can only be achieved by restating the DNS client service, running ipconfig /flushdns or restarting the client.

Now on to bullet point three and our example above.  The Windows DNS client will use the Preferred DNS server first.  If that server fails to respond, even just for a second, the Windows DNS client will switch over to the Alternate DNS server.  The Windows DNS client will not switch back to the Preferred DNS server unless the alternate fails to respond.  In the case of a public DNS server this is unlikely to happen.  If the Windows DNS client does get “stuck” on the alternate server there are three ways to get it to switch back; restart the DNS client service, restart the computer, or modify the DNS client configuration.

So now we have a better understanding of how DNS name resolution and the Windows DNS client work.  Let’s go over why public DNS servers should not be used.  In most environments there will be DNS timeouts on occasion.  As we now understand a DNS timeout can cause the DNS client to switch to the next DNS server in the list.  If the DNS client switches to a public DNS server then queries for internal resources, such as domain controller service records, or other systems on the LAN (Local Area Network), will fail.  So the bottom line here is that using an external DNS server in the DNS client settings can and usually will cause unpredictable behavior.

One final thought.  The default configuration of the Microsoft DNS server will allow Internet names to be resolved.  This is accomplished using root hints.  If a public DNS server must be used for Internet queries, then a DNS forwarder can be added in the DNS server configuration.

I hope you found this article informative.  If you have anything to add or see something that needs a correction, please leave a comment below.

 

 

 

 

 

 

 

 

 

 

We couldn’t create a new partition or locate an existing one.

Posted on by Glenn

Good afternoon.  I ran into an issue today I have seen quite a few times.  I had a customer that was trying to load Windows 2012 on a server.  No matter what he tried he would always receive the same error.

“We couldn’t create a new partition or locate an existing one.”
partition error.png

At first glance it might seem like there is an issue with the disk.  That is not the case though.  The problem has to do with the boot priority as setup in the BIOS of the system.  In this case my customer had a Dell server with an SD card.  He had ordered the server with ESXi loaded on the SD card.  Therefore Dell had put the SD card at the top of the boot priority when it was configured at the factory.  The raid controller was second in the boot priority.  The reason this is a problem is that Windows setup needs to create or use an existing partition on the first device in the boot priority.  Compounding the issue is that, when using the setup, Windows can only be loaded on a fixed disk.  Therefore the error is due to the inability to create a system reserved partition for the boot loader files.

Keep in mind this issue can happen on any system that has more than one entry in the boot priority.  For instance, I have also seen this problem when there were multiple hard disk controllers in a server and the wrong one is at the top of the list.

The fix is quite simple.  Go into the bios and change the boot priority to put the device that will have Windows loaded on it at the top.

I hope you have found this article informative.  If you have anything to add, please use the comments section below.

Why are my computers not showing up on the Network in Windows explorer?

Posted on by Glenn

I ran across an interesting issue this morning.  I had a customer who was not able to browse for computers on most of his workstations and servers.  The problem seemed to start within the last two weeks.

I checked the workstation, DNS client, network list, and network location awareness services.  They were all running.  The problem turned out to be the Function Discovery Resource Publication service.  This service was not started and was set to manual.  Without this service the computer will not advertise itself and will not be able to discover other computers on the network.

So if no computers are showing in Network in Windows Explorer check the Function Discovery Resource Publication service and verify it is running.  I would also recommend setting it to Automatic start so that everything works correctly after a reboot.

I hope this article has been informative.  If you have anything to add, please use the comments section below.