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MKUZIP(8)		     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 in such a way that the
     geom_uzip(4) class will be able to decompress resulting image in  run-time.
     This  allows for significant reduction of size of disk image at the expense
     of some CPU time required to decompress the data each time it is read.  In-
     ternally, operation is done in two phases as follows:

     1.   An infile image is split into clusters and each cluster compressed us-
	  ing zlib(3).

     2.   Resulting set of compressed clusters along with  headers  allowing  to
	  independently  locate  each  individual cluster is written into output
	  file.

     The options are:

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

     -s cluster_size
	     Use cluster_size as the size of chunks  the  file	being  split  up
	     into.   Default value is 16384 bytes.  The cluster_size should be a
	     multiple of 512 bytes.

     -v      Display verbose messages.

NOTES
     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 the gzip(1) utlity.	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 several bytes from that cluster have to be read.

     The  mkuzip inserts tiny shell script at the beginning of the generated im-
     age, which makes it possible to "run" the image just like any  other  shell
     script.   This script tries to load geom_uzip(4) class if it is not loaded,
     configure image as an md(4) disk device using mdconfig(8) utility, and  au-
     tomatically  mount it using mount_cd9660(8) utility to the mount point pro-
     vided as a first argument.

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 6.0		       September 10, 2004		       MKUZIP(8)
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