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 im - age in runtime. 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. Internally, operation is done in two phases as fol - lows:
- 1. An infile image is split into clusters and each cluster
- compressed
using 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 be - ing 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 over - head 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
image, 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 mdcon - fig(8) utility, and automatically mount it using mount_cd9660(8) utili
- ty to the
mount point provided as a first argument.
EXIT STATUS SEE ALSO
gzip(1), zlib(3), geom(4), geom_uzip(4), md(4), mdconfig(8),
mount_cd9660(8)
AUTHORS
- Maxim Sobolev <sobomax@FreeBSD.org>
- BSD September 10, 2004