MKUZIP(8) BSD System Manager's Manual MKUZIP(8)NAMEmkuzip — compress disk image for use with geom_uzip(4) class
SYNOPSISmkuzip [-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 ALSOgzip(1), zlib(3), geom(4), geom_uzip(4), md(4), mdconfig(8),
mount_cd9660(8)AUTHORS
Maxim Sobolev ⟨sobomax@FreeBSD.org⟩
BSD March 17, 2006 BSD
