How can I view the allocation unit size of a NTFS partition in Vista

Question

Which built in  if any  tool can I use to determine the allocation unit size of a certain NTFS partition

User · Answer

The simple GUI way  as provided by J Y in a previous answer    Create a small file  not empty  Right-click  choose Properties Check  Size on disk   in tab General   double-check that your file size is less than half that so that it is certainly using a single allocation unit    This works well and reminds you of the significance of allocation unit size  But it does have a caveat  as seen in comments to previous answer  Windows will sometimes show  Size on disk  as 0 for a very small file  In my testing  NTFS filesystems with allocation unit size 4096 bytes required the file to be 800 bytes to consistently avoid this issue  On FAT32 file systems this issue seems nonexistent  even a single byte file will work - just not empty

User · Answer

start   run   MSINFO32   goto components   goto storage  goto disk  on the right look for Bytes Sector

User · Answer

Open an administrator command prompt  and do this command   fsutil fsinfo ntfsinfo  your drive    The Bytes Per Cluster is the equivalent of the allocation unit

User · Answer

I know this is an old thread  but there s a newer way then having to use fsutil or diskpart   Run this powershell command   Get-Volume    Format-List AllocationUnitSize  FileSystemLabel

User · Answer

The simple GUI way  as provided by J Y in a previous answer    Create a small file  not empty  Right-click  choose Properties Check  Size on disk   in tab General   double-check that your file size is less than half that so that it is certainly using a single allocation unit    This works well and reminds you of the significance of allocation unit size  But it does have a caveat  as seen in comments to previous answer  Windows will sometimes show  Size on disk  as 0 for a very small file  In my testing  NTFS filesystems with allocation unit size 4096 bytes required the file to be 800 bytes to consistently avoid this issue  On FAT32 file systems this issue seems nonexistent  even a single byte file will work - just not empty

User · Answer

The value for BYTES PER CLUSTER - 65536   64K  C  temp gt fsutil fsinfo drives  Drives  C   D   E   F   G   I   J   N   O   P   S    C  temp gt fsutil fsinfo ntfsInfo N  NTFS Volume Serial Number         0xfe5a90935a9049f3 NTFS Version                      3 1 LFS Version                       2 0 Number Sectors                    0x00000002e15befff Total Clusters                    0x000000005c2b7dff Free Clusters                     0x000000005c2a15f0 Total Reserved                    0x0000000000000000 Bytes Per Sector                  512 Bytes Per Physical Sector         512 Bytes Per Cluster                 4096 Bytes Per FileRecord Segment      1024 Clusters Per FileRecord Segment   0 Mft Valid Data Length             0x0000000000040000 Mft Start Lcn                     0x00000000000c0000 Mft2 Start Lcn                    0x0000000000000002 Mft Zone Start                    0x00000000000c0000 Mft Zone End                      0x00000000000cc820 Resource Manager Identifier       560F51B2-CEFA-11E5-80C9-98BE94F91273  C  temp gt fsutil fsinfo ntfsInfo N  NTFS Volume Serial Number         0x36acd4b1acd46d3d NTFS Version                      3 1 LFS Version                       2 0 Number Sectors                    0x00000002e15befff Total Clusters                    0x0000000005c2b7df Free Clusters                     0x0000000005c2ac28 Total Reserved                    0x0000000000000000 Bytes Per Sector                  512 Bytes Per Physical Sector         512 Bytes Per Cluster                 65536 Bytes Per FileRecord Segment      1024 Clusters Per FileRecord Segment   0 Mft Valid Data Length             0x0000000000010000 Mft Start Lcn                     0x000000000000c000 Mft2 Start Lcn                    0x0000000000000001 Mft Zone Start                    0x000000000000c000 Mft Zone End                      0x000000000000cca0 Resource Manager Identifier       560F51C3-CEFA-11E5-80C9-98BE94F91273

User · Answer

According to Microsoft  the allocation unit size  Specifies the cluster size for the file system  - so it is the value shown for  Bytes Per Cluster  as shown in   fsutil fsinfo ntfsinfo C

User · Answer

You can use SysInternals NTFSInfo by Mark Russinovich from the command line and it converts fsutil fsinfo ntfsinfo into more readable information  especially MFT Table info

User · Answer

from the commandline   chkdsk l   wait for the scan to finish   sizdir32 http   www ltr-data se opencode html

User · Answer

Another way to find it quickly via the GUI on any windows system    create a text file  type a word or two  or random text  in it  and save it  Right-click on the file to show Properties   Size on disk    allocation unit

User · Answer

Use diskpart exe   Once you are in diskpart select volume  lt VolumeNumber gt  then type filesystems   It should tell you the file system type and the allocation unit size   It will also tell you the supported sizes etc  Previously mentioned fsutil does work  but answer isn t as clear and I couldn t find a syntax to get the same information for a junction point

User · Answer

Another way to find it quickly via the GUI on any windows system    create a text file  type a word or two  or random text  in it  and save it  Right-click on the file to show Properties   Size on disk    allocation unit

User · Answer

Open an administrator command prompt  and do this command   fsutil fsinfo ntfsinfo  your drive    The Bytes Per Cluster is the equivalent of the allocation unit

User · Answer

from the commandline   chkdsk l   wait for the scan to finish   sizdir32 http   www ltr-data se opencode html

User · Answer

Open an administrator command prompt  and do this command   fsutil fsinfo ntfsinfo  your drive    The Bytes Per Cluster is the equivalent of the allocation unit

User · Answer

Open an administrator command prompt  and do this command   fsutil fsinfo ntfsinfo  your drive    The Bytes Per Cluster is the equivalent of the allocation unit

User · Answer

Use diskpart exe   Once you are in diskpart select volume  lt VolumeNumber gt  then type filesystems   It should tell you the file system type and the allocation unit size   It will also tell you the supported sizes etc  Previously mentioned fsutil does work  but answer isn t as clear and I couldn t find a syntax to get the same information for a junction point

User · Answer

The value for BYTES PER CLUSTER - 65536   64K  C  temp gt fsutil fsinfo drives  Drives  C   D   E   F   G   I   J   N   O   P   S    C  temp gt fsutil fsinfo ntfsInfo N  NTFS Volume Serial Number         0xfe5a90935a9049f3 NTFS Version                      3 1 LFS Version                       2 0 Number Sectors                    0x00000002e15befff Total Clusters                    0x000000005c2b7dff Free Clusters                     0x000000005c2a15f0 Total Reserved                    0x0000000000000000 Bytes Per Sector                  512 Bytes Per Physical Sector         512 Bytes Per Cluster                 4096 Bytes Per FileRecord Segment      1024 Clusters Per FileRecord Segment   0 Mft Valid Data Length             0x0000000000040000 Mft Start Lcn                     0x00000000000c0000 Mft2 Start Lcn                    0x0000000000000002 Mft Zone Start                    0x00000000000c0000 Mft Zone End                      0x00000000000cc820 Resource Manager Identifier       560F51B2-CEFA-11E5-80C9-98BE94F91273  C  temp gt fsutil fsinfo ntfsInfo N  NTFS Volume Serial Number         0x36acd4b1acd46d3d NTFS Version                      3 1 LFS Version                       2 0 Number Sectors                    0x00000002e15befff Total Clusters                    0x0000000005c2b7df Free Clusters                     0x0000000005c2ac28 Total Reserved                    0x0000000000000000 Bytes Per Sector                  512 Bytes Per Physical Sector         512 Bytes Per Cluster                 65536 Bytes Per FileRecord Segment      1024 Clusters Per FileRecord Segment   0 Mft Valid Data Length             0x0000000000010000 Mft Start Lcn                     0x000000000000c000 Mft2 Start Lcn                    0x0000000000000001 Mft Zone Start                    0x000000000000c000 Mft Zone End                      0x000000000000cca0 Resource Manager Identifier       560F51C3-CEFA-11E5-80C9-98BE94F91273

User · Answer

Another way to find it quickly via the GUI on any windows system    create a text file  type a word or two  or random text  in it  and save it  Right-click on the file to show Properties   Size on disk    allocation unit

User · Answer

Easiest way  confirmed on 2012r2    Go to  This PC  Right click on the Disk Click on Format   Under drop down  allocation unit size  will be the value of what the Allocation of the Unit size disk already is

User · Answer

start   run   MSINFO32   goto components   goto storage  goto disk  on the right look for Bytes Sector

User · Answer

You can use SysInternals NTFSInfo by Mark Russinovich from the command line and it converts fsutil fsinfo ntfsinfo into more readable information  especially MFT Table info

User · Answer

Another way to find it quickly via the GUI on any windows system    create a text file  type a word or two  or random text  in it  and save it  Right-click on the file to show Properties   Size on disk    allocation unit

User · Answer

The value for BYTES PER CLUSTER - 65536   64K  C  temp gt fsutil fsinfo drives  Drives  C   D   E   F   G   I   J   N   O   P   S    C  temp gt fsutil fsinfo ntfsInfo N  NTFS Volume Serial Number         0xfe5a90935a9049f3 NTFS Version                      3 1 LFS Version                       2 0 Number Sectors                    0x00000002e15befff Total Clusters                    0x000000005c2b7dff Free Clusters                     0x000000005c2a15f0 Total Reserved                    0x0000000000000000 Bytes Per Sector                  512 Bytes Per Physical Sector         512 Bytes Per Cluster                 4096 Bytes Per FileRecord Segment      1024 Clusters Per FileRecord Segment   0 Mft Valid Data Length             0x0000000000040000 Mft Start Lcn                     0x00000000000c0000 Mft2 Start Lcn                    0x0000000000000002 Mft Zone Start                    0x00000000000c0000 Mft Zone End                      0x00000000000cc820 Resource Manager Identifier       560F51B2-CEFA-11E5-80C9-98BE94F91273  C  temp gt fsutil fsinfo ntfsInfo N  NTFS Volume Serial Number         0x36acd4b1acd46d3d NTFS Version                      3 1 LFS Version                       2 0 Number Sectors                    0x00000002e15befff Total Clusters                    0x0000000005c2b7df Free Clusters                     0x0000000005c2ac28 Total Reserved                    0x0000000000000000 Bytes Per Sector                  512 Bytes Per Physical Sector         512 Bytes Per Cluster                 65536 Bytes Per FileRecord Segment      1024 Clusters Per FileRecord Segment   0 Mft Valid Data Length             0x0000000000010000 Mft Start Lcn                     0x000000000000c000 Mft2 Start Lcn                    0x0000000000000001 Mft Zone Start                    0x000000000000c000 Mft Zone End                      0x000000000000cca0 Resource Manager Identifier       560F51C3-CEFA-11E5-80C9-98BE94F91273

User · Answer

According to Microsoft  the allocation unit size  Specifies the cluster size for the file system  - so it is the value shown for  Bytes Per Cluster  as shown in   fsutil fsinfo ntfsinfo C

User · Answer

I know this is an old thread  but there s a newer way then having to use fsutil or diskpart   Run this powershell command   Get-Volume    Format-List AllocationUnitSize  FileSystemLabel

User · Answer

Open an administrator command prompt  and do this command   fsutil fsinfo ntfsinfo  your drive    The Bytes Per Cluster is the equivalent of the allocation unit

User · Answer

Easiest way  confirmed on 2012r2    Go to  This PC  Right click on the Disk Click on Format   Under drop down  allocation unit size  will be the value of what the Allocation of the Unit size disk already is

User · Answer

The value for BYTES PER CLUSTER - 65536   64K  C  temp gt fsutil fsinfo drives  Drives  C   D   E   F   G   I   J   N   O   P   S    C  temp gt fsutil fsinfo ntfsInfo N  NTFS Volume Serial Number         0xfe5a90935a9049f3 NTFS Version                      3 1 LFS Version                       2 0 Number Sectors                    0x00000002e15befff Total Clusters                    0x000000005c2b7dff Free Clusters                     0x000000005c2a15f0 Total Reserved                    0x0000000000000000 Bytes Per Sector                  512 Bytes Per Physical Sector         512 Bytes Per Cluster                 4096 Bytes Per FileRecord Segment      1024 Clusters Per FileRecord Segment   0 Mft Valid Data Length             0x0000000000040000 Mft Start Lcn                     0x00000000000c0000 Mft2 Start Lcn                    0x0000000000000002 Mft Zone Start                    0x00000000000c0000 Mft Zone End                      0x00000000000cc820 Resource Manager Identifier       560F51B2-CEFA-11E5-80C9-98BE94F91273  C  temp gt fsutil fsinfo ntfsInfo N  NTFS Volume Serial Number         0x36acd4b1acd46d3d NTFS Version                      3 1 LFS Version                       2 0 Number Sectors                    0x00000002e15befff Total Clusters                    0x0000000005c2b7df Free Clusters                     0x0000000005c2ac28 Total Reserved                    0x0000000000000000 Bytes Per Sector                  512 Bytes Per Physical Sector         512 Bytes Per Cluster                 65536 Bytes Per FileRecord Segment      1024 Clusters Per FileRecord Segment   0 Mft Valid Data Length             0x0000000000010000 Mft Start Lcn                     0x000000000000c000 Mft2 Start Lcn                    0x0000000000000001 Mft Zone Start                    0x000000000000c000 Mft Zone End                      0x000000000000cca0 Resource Manager Identifier       560F51C3-CEFA-11E5-80C9-98BE94F91273

User · Answer

Open an administrator command prompt  and do this command   fsutil fsinfo ntfsinfo  your drive    The Bytes Per Cluster is the equivalent of the allocation unit

[windows-vista] How can I view the allocation unit size of a NTFS partition in Vista?

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