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FALLOCATE(1)				  User Commands 			     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 fal-
       locate system call, this is done quickly by allocating blocks and marking them  as  unini-
       tialized, 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
       The  length  and offset arguments may be followed by the multiplicative suffixes KiB=1024,
       MiB=1024*1024, and so on for GiB, TiB, PiB, EiB, ZiB and YiB (the "iB" is  optional,  e.g.
       "K"  has  the  same meaning as "KiB") or the suffixes KB=1000, MB=1000*1000, and so on for
       GB, TB, PB, EB, ZB and YB.

       -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.

       -l, --length length
	      Specifies the length of the allocation, in bytes.

       -h, --help
	      Print help and exit.

       -V, --version
	      Print version and exit.

AUTHORS
       Eric Sandeen <sandeen@redhat.com>
       Karel Zak <kzak@redhat.com>

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

AVAILABILITY
       The fallocate command is part of the util-linux package and is available from Linux Kernel
       Archive <ftp://ftp.kernel.org/pub/linux/utils/util-linux/>.

util-linux				  September 2011			     FALLOCATE(1)
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