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Files on a home computer that are compressed by using NTFS compression may not be backed up correctly by Windows Home Server

Article ID: 950190 - View products that this article applies to.

SYMPTOMS

On a home computer, you can compress some files by using NTFS compression through advanced attributes settings. In some cases, these files may not be backed up correctly by Windows Home Server. If you try to restore a compressed file from a Windows Home Server backup, the file may be corrupted.

Note Any Windows Home Server backup that includes NTFS compressed files may have this issue.

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CAUSE

This issue occurs because of the way Windows Home Server backs up files that are compressed by using NTFS compression.

Under certain circumstances, a compressed file may consume more disk space than the original file size. Some sections of a file may use less disk space after NTFS compression. However, other sections of a file may use more disk space after NTFS compression. If the compressed file uses more disk space than the original file, a small amount of data at the end of the file may be lost during the backup process. This data loss results in a corrupted file or a partially corrupted file, depending on the corresponding file types. The file types that may be affected by this issue include, but are not limited to, CAB, ZIP, JPG, and PNG.

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RESOLUTION

An update is available for the Windows Home Server Connector software. This update makes sure that NTFS compressed files are backed up correctly. You can download the update from the Microsoft Download Center. Then, you can install the update on all the home computers that have the Windows Home Server Connector software installed.

After you install this update, NTFS compressed files are backed up correctly. However, backups that you created before you installed the update may still contain corrupted files if the backups used NTFS compression.

This update will also be available as an update on the Microsoft Windows Update Web site.

Note This update is replaced by Windows Home Server Power Pack 1.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

944289

(http://support.microsoft.com/kb/944289/ )

Description of the Windows Home Server Power Pack 1 update

Update information

The following file is available for download from the Microsoft Download Center:

Collapse this imageExpand this image

Download the update for Windows Home Server (KB950190) package now.

(http://go.microsoft.com/fwlink/?LinkId=117355)

For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base:

119591

(http://support.microsoft.com/kb/119591/ )

How to obtain Microsoft support files from online services

Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.

Prerequisites

To apply this update, you must have the latest version of Windows Home Server Connector installed on the home computer.

Pre-installation requirement

Before you install this update, make sure that you are not running home computer backup.

Restart requirement

After you apply this update, you do not have to restart the computer.

Update replacement information

This update does not replace any other previously released updates.

File information

The English version of this update has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Collapse this tableExpand this table

File name	File version	File size	Date	Time	Platform
Backupengine.exe	6.0.1500.10	62,496	23-Apr-2008	23:08	x86
Backuputil.dll	6.0.1500.10	123,936	23-Apr-2008	23:08	x86

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STATUS

Microsoft has confirmed that this is an issue in the Microsoft products that are listed in the "Applies to" section.

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MORE INFORMATION

Some computers may not meet the prerequisites of this update. In this case, you may turn off NTFS compression for each compressed hard disk or folder. To do this, follow these steps:

Right-click the compressed hard disk or folder, and then click Properties.
On the General tab, click Advanced to open the Advanced Attributes dialog box.
In the Advanced Attributes dialog box, click to clear the Compress contents to save disk space check box, and then click OK.

By default, the name of a compressed hard disk or folder appears in a blue font in Windows Explorer instead of the standard black font. After you turn off NTFS compression for the target, the name returns to the standard black font.

After NTFS compression is turned off on a home computer, Windows Home Server will back up the newly uncompressed files on that home computer during the next backup to the Windows Home Server. If you want to back up a home computer immediately, right-click the Windows Home Server tray icon, and then click Backup Now.

You can also use the compact command to make sure that no files are compressed by using NTFS compression. To do this, use an account that has administrative credentials to open a Command Prompt window. Type the following command. Replace the disk placeholder with the disk letter of the disk on your home computer.

compact /U /S /I disk:\*.*

For example, if you want to turn off compression for all files on disk C, use the following command:

compact /U /S /I C:\*.*

Determine whether you have compressed files that are not backed up correctly

To determine whether you have any files on a home computer that are compressed by using NTFS compression and that may not have been backed up correctly, follow these steps:

Use an account that has administrative credentials to open a Command Prompt window.
Run the following command for each hard disk that is attached to the home computer that is backed up by Windows Home Server. Replace the disk placeholder with the disk letter of the hard disk.
1. Carefully type the following command at the command prompt, and then press ENTER. This command creates a text file that is named disk.txt in a temporary directory. The file lists the file names of all files that are compressed on the hard disk.
  compact /s:disk:\ | findstr /c:" to 1 C " > %temp%\disk.txt
  
  For example, run the following command for files on disk C:
  compact /s:C:\ | findstr /c:" to 1 C "> %temp%\C.txt
2. Use the following command to view the file that you created in step a:
  notepad %temp%\disk.txt
  For example, run the following command to view the file that you created in step a:
  notepad %temp%\C.txt

Files that are identified by this method are compressed by NTFS. This does not mean that they have not been backed up correctly because of the issue that is mentioned in this article. It only means that the files may not have been backed up correctly.

The Connector software for the Windows Home Server operating system connects your home computers to your home server. Windows Home Server then automatically backs up your home computer, monitors its health, and enables you to configure and to remotely administer Windows Home Server from your home computer.

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