2015-02-02 12:34:26 -05:00
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.Dd February 2, 2015
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.Dt FALLOCATE 1
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.Os ubase
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.Sh NAME
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.Nm fallocate
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.Nd preallocate blocks to a file
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.Sh SYNOPSIS
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.Nm
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.Op Fl o Ar offset
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.Fl l Ar length Ar file
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.Sh DESCRIPTION
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.Nm
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preallocates blocks to a file. Only certain filesystems support the
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.Xr fallocate 2
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system call. This is a very fast operation to allocate uninitialized blocks
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in a file without doing any IO. As of the Linux kernel v2.6.31, the
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.Xr fallocate 2
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system call is supported by the btrfs, ext4, ocfs2, and xfs filesystems.
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.Sh OPTIONS
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.Bl -tag -width Ds
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.It Fl l Ar length
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2014-04-13 11:40:40 -04:00
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Specifies the length of the allocation, in bytes.
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2015-02-02 12:34:26 -05:00
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.It Fl o
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Specifies the beginning offset of the allocation, in bytes.
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.El
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.Sh SEE ALSO
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.Xr fallocate 2
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