GEOM_UZIP(4FREEBSD) - man page online | special files

GEOM based compressed disk images.

October 9, 2006
GEOM_UZIP(4)                       BSD Kernel Interfaces Manual                      GEOM_UZIP(4)


geom_uzip — GEOM based compressed disk images


To compile this driver into the kernel, place the following line in your kernel configura‐ tion file: options GEOM_UZIP Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5): geom_uzip_load="YES"


The geom_uzip framework provides support for compressed read only disk images. This allows significant storage savings at the expense of a little CPU time on each read. Data written in the GEOM label area allows geom_uzip to detect compressed images which have been created with mkuzip(8) and presented to the kernel as a logical disk device via md(4). geom_uzip creates a unique md#.uzip device for each image. The geom_uzip device is subsequently used by the FreeBSD kernel to access the disk images. The geom_uzip driver does not allow write operations to the underlying disk image. To check which md(4) devices match a given geom_uzip device: # geom uzip list Geom name: md1.uzip Providers: 1. Name: md1.uzip Mediasize: 22003712 (21M) Sectorsize: 512 Mode: r1w0e1 Consumers: 1. Name: md1 Mediasize: 9563648 (9.1M) Sectorsize: 512 Mode: r1w0e1


GEOM(4), md(4), geom(8), mkuzip(8)


The geom_uzip driver was written by Max Khon <>. This manual page was writ‐ ten by Ceri Davies <>.
BSD October 9, 2006 BSD
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geom_uzip(4freebsd) referred by
refer to md(4)