An update that improves the compatibility of Windows 7 and Windows Server 2008 R2 with Advanced Format Disks is available

The Extensible Storage Engine API(ESENT) is a high-performance desktop database engine that is used by many applications, including Windows Update. Certain storage drivers have different kinds of support for querying the physical sector size of the hard disk in a hard disk drive and, when such a driver is upgraded, the reported physical sector size of the hard disk can change. Because of the logging structure of ESENT, applications that are built on ESENT receive an error message and stop responding when the reported physical sector size changes between operating system sessions.

Note Applications that are built on ESENT include Windows Update, Active Directory, Windows Desktop Search, certification authority (CA), WINS, DHCP, and Windows Live Mail.

You receive the following error message when you click the Check for Updates button on Windows Update site:

Additionally, the following error is logged into the Application log:

An updated Esent.sys binary that eases the effects of changes in the reported sector size is included with this hotfix.

Note Esent.sys does not support physical sector sizes other than 512 bytes and 4 KB.

Database repair

To repair the database, follow these steps:

1. At a command prompt, type the following commands. Press Enter after you type each command.

   • net stop "windows update"

   • cd /d %windir%\SoftwareDistribution\DataStore\Logs

   • esentutl /mh ..\DataStore.edb | findstr /i /c:"State:"

   Note If "State: Clean Shutdown" is displayed in the command-line, go to step 5.

2. Create a temporary folder (for example, create a folder that is named "Fixedfiles" by using the mkdir c:\fixedfiles command).
   
   Note During the following steps, replace "c:\fixedfiles" with the folder that you created in this step.

3. Obtain a copy of the %windir%\system32\esent.dll file from a computer that has this hotfix installed, and copy the file to c:\fixedfiles.

4. At a command prompt, type the following commands. Press Enter after you type each command.

   • copy %windir%\system32\esentutl.exe c:\fixedfiles\

   • c:\fixedfiles\esentutl.exe /r edb

   • esentutl /mh ..\datastore.edb | findstr /i /c:"State:"

   Notes

   • If "State: Clean Shutdown" is displayed in the command-line, go to step 5.

   • If this step fails or if "State: Clean Shutdown" is not displayed in the command-line, see the "Destructive recovery method" section of this article.

5. Create a temporary folder (for example, create a folder that is named "Backuplogs" by using the mkdir c:\backuplogs command).
   
   Note During the following steps, replace "c:\backuplogs" with the folder that you created in this step.

6. At a command prompt, type the following commands. Press Enter after you type each command.

   • move * c:\backuplogs

   • net start "windows update"

7. Run Windows Update.

Destructive recovery method

Important If you use this method, you will lose your Windows Update history. Therefore, we do not recommend that you use this method unless you cannot repair the database. To use the destructive recovery method, follow these steps:

1. At a command prompt, type the following commands. Press Enter after you type each command.

   • net stop "windows update"

   • cd /d windir%\SoftwareDistribution\DataStore

   • rmdir /s/q Logs

   • del DataStore.mdb

   • net start "windows update"

2. Run Windows Update.

Before Advanced Format disks were available, NTFS assumed that the logical sector size that was exposed by the disk interface was equal to the physical sector size of the disk. Although NTFS was originally designed to theoretically support larger sectors sizes, NTFS assumed that these two sector sizes were equal. When NTFS performs buffered writes at the end of a file in Windows 7 and Windows Server 2008 R2, NTFS pads the write operation to the end of the sector size which is exposed by the disk interface (the logical sector size). This behavior guarantees sector alignment. However, because the size of a logical sector of a 512e drive is 512 bytes, the buffered write does not align to the physical sector size of the drive’s hard disk. This causes the Advanced Format disk to internally update the 512-byte logical sector within its 4KB physical sector, which can result in performance and reliability issues.

This hotfix introduces behavior to NTFS which makes sure that buffered writes at the end of the file are padded to the reported physical sector size of the disk.

This issue can manifest itself with everyday applications on an Advanced Format disk. However, this issue occurs most frequently when you perform many small writes, such as using the ImageX command-line tool in Windows 7 or in Windows Server 2008 R2 to apply a Microsoft Windows Image (.wim file) to an Advanced Format disk. Without the hotfix, ImageX takes significantly longer to complete the operation than if you were to apply the same operation to a traditional hard disk.

Note This fix is dependent on the storage driver and the disk both reporting the correct physical sector size. NTFS does not support disks which have reported physical sector sizes other than 512-bytes or 4-KB, or on disks whose logical sector size is not 512-bytes.

USBStor is the Microsoft USB storage port driver that is automatically loaded for a device that complies with the USB mass storage class. The USBStor driver inbox with Windows 7 does not support the IOCTL_STORAGE_QUERY_PROPERTY request with the STORAGE_ACCESS_ALIGNMENT_DESCRIPTOR structure to retrieve the storage access alignment descriptor data for an attached disk. This structure contains physical and logical sector size information, and without this information, NTFS and other applications cannot perform aligned writes to the USB storage device which can adversely affect performance and reliability.

Without this hotfix, applications cannot query the physical sector size of the external storage device.

An updated USBStor driver (Usbstor.sys) which supports the IOCTL_STORAGE_QUERY_PROPERTY request, together with the STORAGE_ACCESS_ALGINMENT_DESCRIPTOR structure, is included in this hotfix.

Note The IOCTL_STORAGE_QUERY_PROPERTY request results in a translation to the SCSI SBC3 READ_CAPACITY(16) command. The attached USB device must correctly report the sector size information through the SBC3 READ_CAPACITY(16) command. The attached USB device must also guarantee that as a response to the initial INQUIRY command, 0x04C0 (SBC3 No Specified Version) is returned as the version descriptor.

For more information about the IOCTL_STORAGE_QUERY_PROPERTY control code, visit the following Microsoft site:

General information about the IOCTL_STORAGE_QUERY_PROPERTY control code

For more information about the STORAGE_ACCESS_ALIGNMENT_DESCRIPTOR structure, visit the following Microsoft site:

General information about the STORAGE_ACCESS_ALIGNMENT_DESCRIPTOR structure

Storport is a storage driver model that is used by many storage controller manufacturers. It is included with Windows 7 and Windows Server 2008 R2. Storport does not support the IOCTL_STORAGE_QUERY_PROPERTY request with the STORAGE_ACCESS_ALIGNMENT_DESCRIPTOR structure to retrieve the storage access alignment descriptor data for an attached disk. This structure contains physical and logical sector size information. Without this information, NTFS and other applications cannot perform aligned writes to the disk. This may affect performance and reliability.

Without this hotfix, applications cannot query the physical sector size of the storage device.

An updated Storport driver (Storport .sys) which supports the IOCTL_STORAGE_QUERY_PROPERTY request, together with the STORAGE_ACCESS_ALGINMENT_DESCRIPTOR structure, is included in this hotfix.

Note The IOCTL_STORAGE_QUERY_PROPERTY request results in a translation to the SCSI SBC3 READ_CAPACITY(16) command. The miniport driver which plugs into the Storport driver model must support the SBC3 READ_CAPACITY(16) command. Additionally, the disk must correctly report the sector size information through the SBC3 READ_CAPACITY(16) command.

For more information about the IOCTL_STORAGE_QUERY_PROPERTY control code, visit the following Microsoft site:

General information about the IOCTL_STORAGE_QUERY_PROPERTY control code

For more information about the STORAGE_ACCESS_ALIGNMENT_DESCRIPTOR structure, visit the following Microsoft site:

General information about the STORAGE_ACCESS_ALIGNMENT_DESCRIPTOR structure

Many storage drivers do not support correct sector size reporting for Advanced Format disks. Updates to the following drivers are included in this hotfix:

• IaStorV.sys

• Amdsata.sys

• Nvraid.sys

• Nvsata.sys

Note Other third-party storage drivers may not be updated to support these new SBC3 commands. Please contact your storage controller vendor for more information.

Additionally, this hotfix rollup package includes fixes that are documented in the following Microsoft Knowledge Base articles:

981208 Poor performance when you transfer many small files on a computer that is running Windows 7 or Windows Server 2008 R2

This update also updates the Fsutil.exe tool. The updated tool generates a new "Bytes Per Physical Sector" text in the output. For example, when you run the fsutil fsinfo ntfsinfo C: command to obtain information about drive C:, you receive output that resembles the following:

NTFS Volume Serial Number :       0xfe6e5dcc6e5d7e79
Version :                         3.1
Number Sectors :                  0x000000001d1927ff
Total Clusters :                  0x0000000003a324ff
Free Clusters  :                  0x0000000001f8bae8
Total Reserved :                  0x00000000000007f0
Bytes Per Sector  :               512
Bytes Per Physical Sector :       4096
Bytes Per Cluster :               4096
Bytes Per FileRecord Segment    : 1024
Clusters Per FileRecord Segment : 0
Mft Valid Data Length :           0x0000000020980000
Mft Start Lcn  :                  0x00000000000c0000
Mft2 Start Lcn :                  0x0000000000000002
Mft Zone Start :                  0x000000000109c060
Mft Zone End   :                  0x00000000010a8880
RM Identifier:                    974AD058-3B3D-11DE-9300-000FFEE93BEF 

Notes The value for "bytes per physical sector" can be any of the following:

• 512 – for Legacy 512 Native drives

• 4096 – for Advanced Format drives

• <Not Supported> - if the hardware or driver does not support the IOCTL_STORAGE_QUERY_PROPERTY control code

The English (United States) version of this update 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 7 and Windows Server 2008 R2 file information notes

Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.

For all supported x86-based versions of Windows 7

For all supported x64-based versions of Windows 7 and of Windows Server 2008 R2