NTFSFALLOCATE(8) (June 2014) 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 command, e.g. -fv is equiva-
lent 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 mul-
tiple 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 fac-
tor 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 sig-
nificant time.
-N, --no-action
Simulate the allocation without actually write to
device.
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-o, --offset OFFSET
Specify the offset in the file where preallocation
starts. By default, the preallocation 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 default, the unnamed $DATA
attribute (the contents of a plain file) will be preal-
located. The attribute has to be specified by a number
in decimal or hexadecimal : box; lB lB lB l l l.
Hex Decimal Name 0x10 16 "$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 Win-
dows may crash (BSOD) when writing to preallocated clusters
which were not written to earlier. Files with preallocated
space should be fully be written to before they are updated
by Windows.
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If you find a bug in ntfsfallocate proper, please send an
email describing the problem to the development team:
ntfs-3g-devel@lists.sf.net
AUTHORS
ntfsfallocate was written by Jean-Pierre Andre.
AVAILABILITY
ntfsfallocate is part of the ntfs-3g package and is avail-
able from:
http://www.tuxera.com/community/
SEE ALSO
ntfs-3g(8), ntfstruncate(8), ntfsprogs(8), fallocate(1)
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