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FALLOCATE(1)                                                      FALLOCATE(1)



NAME
       fallocate - preallocate space to a file.

SYNOPSIS
       fallocate [-n] [-p] [-o offset] -l length filename

DESCRIPTION
       fallocate  is  used  to preallocate blocks to a file.  For filesystems which support the fallocate system call,
       this is done quickly by allocating blocks and marking them as  uninitialized,  requiring  no  IO  to  the  data
       blocks.  This is much faster than creating a file by filling it with zeros.

       As  of  the  Linux  Kernel  v2.6.31,  the fallocate system call is supported by the btrfs, ext4, ocfs2, and xfs
       filesystems.

       The exit code returned by fallocate is 0 on success and 1 on failure.


OPTIONS
       -h, --help
              Print help and exit.

       -n, --keep-size
              Do not modify the apparent length of the file. This may effectively allocate blocks past EOF, which  can
              be removed with a truncate.

       -p, --punch-hole
              Punch holes in the file, the range should not exceed the length of the file.

       -o, --offset offset
              Specifies  the beginning offset of the allocation, in bytes.  Suffixes of k, m, g, t, p, e may be speci-
              fied to denote KiB, MiB, GiB, etc.

       -l, --length length
              Specifies the length of the allocation, in bytes.  Suffixes of k, m, g, t, p,  e  may  be  specified  to
              denote KiB, MiB, GiB, etc.

AUTHORS
       Eric Sandeen <sandeenATredhat.com>
       Karel Zak <kzakATredhat.com>

SEE ALSO
       fallocate(2), posix_fallocate(3), truncate(1)

AVAILABILITY
       The   fallocate   command   is  part  of  the  util-linux-ng  package  and  is  available  from  ftp://ftp.ker-
       nel.org/pub/linux/utils/util-linux-ng/.




Version 1.0                        Jul 2009                       FALLOCATE(1)