Applications that are built on ESENT and that run on a Windows Vista-based or Windows Server 2008-based computer may not work correctly after the reported physical sector size of the storage device changes

Storage devices have traditionally been based on 512-byte sectors. Recently, storage device vendors have begun to transition to storage devices with a sector size of 4,096 bytes (4 KB). These are known as �Advanced Format Disk� or �512e� devices. Although support for these storage devices that have various software and hardware components of a system is improving, support may remain inconsistent. The most common inconsistency is that support for accurate reporting of the physical sector size of these storage devices is inconsistent. Therefore, applications must handle scenarios where the reported physical sector size of the storage device they are operating on may change.�

The following are some examples of scenarios where the physical sector size reported to Windows can potentially change:

• You move the storage device to a RAID controller from a direct-attached controller, and vice-versa. The reported physical sector size may change because RAID controllers may not report the physical sector size of the storage device. Therefore, the system may see 4 KB in one session, but 512 bytes in another session, and vice-versa.
• You upgrade your primary storage device that has a 512-byte physical sector size to a storage device that has a 4-KB physical sector size, or vice-versa. And you perform a block-level backup and restore, such as with Windows backup. Consider the following scenario:
  • You perform a block-level backup of your system that is running on a storage device that reports a 512-byte physical sector size.
  • You replace that storage device by using a storage device that reports a 4-KB physical sector size.
  • You perform a block-level restore of your system to the new storage device.
  In this scenario, the reported physical sector size is changed from 512 bytes to 4 KB when the system starts.
  
  Note�This scenario can also be reversed where you replace a storage device that uses a 4-KB physical sector size to a storage device that uses a 512-byte physical sector size.
• You upgrade the storage controller in the system where the current storage controller has support for physical sector size reporting, and the new storage controller does not have support for physical sector size reporting, or vice-versa. When the storage controller changes, Windows must load the appropriate driver to support the storage controller. This issue occurs most frequently when you are upgrading from the Microsoft Inbox ATA driver (MSAHCI) to a third-party Storport-based driver, or vice-versa.
• You change the mode of the storage controller in your system�s BIOS. This issue may occur in all combinations of modes such as AHCI, Legacy, IDE, Compatible, RAID, and so on. Each mode requires a different storage driver to be loaded by Windows. In this case,�some drivers may have support and other drivers may not have support.�

The following are examples of applications that are built on the Extensible Storage Engine API (ESENT):

• Windows Update
• Active Directory
• Windows Desktop Search
• Certification authority (CA)
• Windows Internet Name Service (WINS)
• Dynamic Host Configuration Protocol (DHCP)
• Windows Live Mail

As an example of how this issue may manifest itself for Windows Update, you may receive the following error message:
Additionally, an event that resembles the following is logged in the application event log:

Log Name: Application
Source: ESENT
Date: <date & time>
Event ID: 412
Task Category: Logging/Recovery
Level: Error
Keywords: Classic
User: N/A
Computer: <computer name>
Description:
wuaueng.dll (936) SUS20ClientDataStore: Unable to read the header of logfile C:\Windows\SoftwareDistribution\DataStore\Logs\edb.log. Error -546.

Note:�This issue only occurs in Windows Vista and in Windows Server 2008. For information about this issue on Windows 7 and�Windows Server 2008 R2, click the following article number to view the article in the Microsoft Knowledge Base:

This issue occurs because the physical sector size that is reported by the storage device changes. Although ESENT was designed with support for 512-byte and 4-KB physical sector sizes during the initial database creation, ESENT expects that the reported physical sector size remains consistent between sessions. When the ESENT database re-initializes, it makes sure that the physical sector size that the database was created for and the current reported physical sector size are the same. When the sector sizes are different, ESENT reports an error.

To work around this issue, you may try to revert the system to a point before one of the sample scenarios occurred. For example, you may try to restore the previous storage driver.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft website: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

Prerequisites

To apply this hotfix, you must be running one of the following operating systems:

• Windows Vista Service Pack 1 (SP1)
• Windows Vista Service Pack 2 (SP2)
• Windows Server 2008
• Windows Server 2008 Service Pack 2 (SP2)

For more information about how to obtain a Windows Vista service pack, click the following article number to view the article in the Microsoft Knowledge Base: For more information about how to obtain a Windows Server 2008 service pack, click the following article number to view the article in the Microsoft Knowledge Base:

Registry information

To use the hotfix in this package, you do not have to make any changes to the registry.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The English (United States) version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.

Windows Vista and Windows Server 2008 file information notes

Important Windows Vista hotfixes and Windows Server 2008 hotfixes are included in the same packages. However, only "Windows Vista" is listed on the Hotfix Request page. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows Vista" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.

• The files that apply to a specific product, SR_Level (RTM, SPn), and service branch (LDR, GDR) can be identified by examining the file version numbers as shown in the following table.
  Collapse this tableExpand this table

  Version	Product	SR_Level	Service branch
  6.0.600 1 . 22xxx	Windows Vista and Windows Server 2008	SP1	LDR
  6.0.600 2 . 22xxx	Windows Vista and Windows Server 2008	SP2	LDR

• Service Pack 1 is integrated into the release version of Windows Server 2008.
• The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. MUM files and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintain the state of the updated components. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.

For all supported x86-based versions of Windows Server 2008 and of Windows Vista

For all supported x64-based versions of Windows Server 2008 and of Windows Vista

For all supported IA-64-based versions of Windows Server 2008

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

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

Additional file information

Additional file information for Windows Vista and for Windows Server 2008

Additional files for all supported x86-based versions of Windows Vista and of Windows Server 2008

Additional files for all supported x64-based versions of Windows Vista and of Windows Server 2008

Additional files for all supported IA-64-based versions of Windows Server 2008