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MKUZIP(8)               FreeBSD System Manager's Manual              MKUZIP(8)

NAME
     mkuzip - compress disk image for use with geom_uzip(4) class

SYNOPSIS
     mkuzip [-v] [-o outfile] [-s cluster_size] infile

DESCRIPTION
     The mkuzip utility compresses a disk image file so that the geom_uzip(4)
     class will be able to decompress the resulting image at run-time.  This
     allows for a significant reduction of size of disk image at the expense
     of some CPU time required to decompress the data each time it is read.
     The mkuzip utility works in two phases:

     1.   An infile image is split into clusters; each cluster is compressed
          using zlib(3).

     2.   The resulting set of compressed clusters along with headers that
          allow locating each individual cluster is written to the output
          file.

     The options are:

     -o outfile
             Name of the output file outfile.  The default is to use the input
             name with the suffix .uzip.

     -s cluster_size
             Split the image into clusters of cluster_size bytes, 16384 bytes
             by default.  The cluster_size should be a multiple of 512 bytes.

     -v      Display verbose messages.

NOTES
     The compression ratio largely depends on the cluster size used.  For
     large cluster sizes (16K and higher), typical compression ratios are only
     1-2% less than those achieved with gzip(1).  However, it should be kept
     in mind that larger cluster sizes lead to higher overhead in the
     geom_uzip(4) class, as the class has to decompress the whole cluster even
     if only a few bytes from that cluster have to be read.

     The mkuzip utility inserts a short shell script at the beginning of the
     generated image, which makes it possible to ``run'' the image just like
     any other shell script.  The script tries to load the geom_uzip(4) class
     if it is not loaded, configure the image as an md(4) disk device using
     mdconfig(8), and automatically mount it using mount_cd9660(8) on the
     mount point provided as the first argument to the script.

EXIT STATUS
     The mkuzip utility exits 0 on success, and >0 if an error occurs.

SEE ALSO
     gzip(1), zlib(3), geom(4), geom_uzip(4), md(4), mdconfig(8),
     mount_cd9660(8)

AUTHORS
     Maxim Sobolev <sobomax@FreeBSD.org>

FreeBSD 11.0-PRERELEASE         March 17, 2006         FreeBSD 11.0-PRERELEASE

NAME | SYNOPSIS | DESCRIPTION | NOTES | EXIT STATUS | SEE ALSO | AUTHORS

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