Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

fallocate(1) [linux man page]

FALLOCATE(1)						      General Commands Manual						      FALLOCATE(1)

NAME
fallocate - preallocate space to a file. SYNOPSIS
fallocate [-n] [-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 allo- cating 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
The length and offset arguments may be followed by binary (2^N) suffixes KiB, MiB, GiB, TiB, PiB and EiB (the "iB" is optional, e.g. "K" has the same meaning as "KiB") or decimal (10^N) suffixes KB, MB, GB, PB and EB. -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. -o, --offset offset Specifies the beginning offset of the allocation, in bytes. -l, --length length Specifies the length of the allocation, in bytes. 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 ftp://ftp.kernel.org/pub/linux/utils/util-linux/. Version 1.0 Jul 2009 FALLOCATE(1)

Check Out this Related Man Page

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 fallocate system call, this is done quickly by allo- cating 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
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)
Man Page