man > ntfsfallocate(8)

NTFSFALLOCATE(8)                       System Manager's Manual                      NTFSFALLOCATE(8)

NAME
       ntfsfallocate - preallocate space to a file on an NTFS volume

SYNOPSIS
       ntfsfallocate [options] -l length device file [attr-type [attr-name]]

DESCRIPTION
       ntfsfallocate  preallocates  space  for  any attribute of a file or directory, thus reserving
       space before actual contents is written. This is similar to fallocate(1).

OPTIONS
       Below is a summary of all the options that ntfsfallocate accepts.  Nearly  all  options  have
       two  equivalent  names.  The short name is preceded by - and the long name is preceded by --.
       Any single letter options, that don't take an argument, can be combined into  a  single  com‐
       mand,  e.g.  -fv is equivalent to -f -v.  Long named options can be abbreviated to any unique
       prefix of their name.

       -f, --force
              This will override some sensible defaults, such as not using a  mounted  volume.   Use
              this option with caution.

       -h, --help
              Show a list of options with a brief description of each one.

       -l, --length LENGTH
              This  is a mandatory option to specify the number of bytes to preallocate.  It will be
              rounded up to a multiple of the cluster size.  A suffix of K, M, G, T, P or E  may  be
              appended to mean a multiplicative factor of a power of 1000. Similarly a suffix of Ki,
              Mi,  Gi,  Ti,  Pi  or Ei may be appended to mean a multiplicative factor of a power of
              1024.

       -n, --no-size-change
              Do not change the apparent size of the file. The space allocated beyond  the  apparent
              size  is not zeroed, but subsequent writing beyond the apparent end of file will force
              zeroing the inner allocated space as it cannot be considered as a hole any  more,  and
              this may take significant time.

       -N, --no-action
              Simulate the allocation without actually write to device.

       -o, --offset OFFSET
              Specify  the offset in the file where preallocation starts. By default, the prealloca‐
              tion is counted from the beginning of the file. Space already allocated  in  the  area
              defined by offset and length is preserved.

       -q, --quiet
              Suppress some debug/warning/error messages.

       -v, --verbose
              Display more debug/warning/error messages.

       -V, --version
              Show the version number, copyright and license of ntfsfallocate.

       attr-type
              Define  a  particular  attribute  type to be preallocated (advanced use only).  By de‐
              fault, the unnamed $DATA attribute (the contents of a plain  file)  will  be  preallo‐
              cated. The attribute has to be specified by a number in decimal or hexadecimal :
              ┌────────────────────────────────────────────┐
              │ Hex     Decimal   Name                     │
              │ 0x10    16        "$STANDARD_INFORMATION"  │
              │ 0x20    32        "$ATTRIBUTE_LIST"        │
              │ 0x30    48        "$FILE_NAME"             │
              │ 0x40    64        "$OBJECT_ID"             │
              │ 0x50    80        "$SECURITY_DESCRIPTOR"   │
              │ 0x60    96        "$VOLUME_NAME"           │
              │ 0x70    112       "$VOLUME_INFORMATION"    │
              │ 0x80    128       "$DATA"                  │
              │ 0x90    144       "$INDEX_ROOT"            │
              │ 0xA0    160       "$INDEX_ALLOCATION"      │
              │ 0xB0    176       "$BITMAP"                │
              │ 0xC0    192       "$REPARSE_POINT"         │
              │ 0xD0    208       "$EA_INFORMATION"        │
              │ 0xE0    224       "$EA"                    │
              │ 0xF0    240       "$PROPERTY_SET"          │
              │ 0x100   256       "$LOGGED_UTILITY_STREAM" │
              └────────────────────────────────────────────┘


       attr-name
              Define  the  name  of  the  particular attribute type to be preallocated (advanced use
              only).

EXAMPLES
       Preallocate 100MB to the file database.db located in the Data directory which is at the  root
       of an NTFS file system.

              ntfsfallocate -l 100M /dev/sda1 Data/database.db


BUGS
       There  are  no  known  problems with ntfsfallocate, however it can lead to configurations not
       supported by Windows and Windows may crash (BSOD) when writing to preallocated clusters which
       were not written to earlier. Files with preallocated space should be fully be written to  be‐
       fore they are updated by Windows.

       If you find a bug in ntfsfallocate proper, please send an email describing the problem to the
       development team:
       ntfs-3g-devel AT lists.net

AUTHORS
       ntfsfallocate was written by Jean-Pierre Andre.

AVAILABILITY
       ntfsfallocate is part of the ntfs-3g package and is available from:
       https://github.com/tuxera/ntfs-3g/wiki/

SEE ALSO
       ntfs-3g(8), ntfstruncate(8), ntfsprogs(8), fallocate(1)

ntfs-3g 2022.10.3                             June 2014                             NTFSFALLOCATE(8)