geom_uncompress(4) [freebsd man page]

GEOM_UNCOMPRESS(4)					   BSD Kernel Interfaces Manual 					GEOM_UNCOMPRESS(4)

NAME

     geom_uncompress -- GEOM based compressed disk images

SYNOPSIS

     To compile this driver into the kernel, place the following line in your kernel configuration file:

	   options GEOM_UNCOMPRESS

     Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

	   geom_uncompress_load="YES"

DESCRIPTION

     The geom_uncompress 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_uncompress to detect compressed images which have been
     created with mkulzma(8) or mkuzip(8) and presented to the kernel as a logical disk device via md(4).  geom_uncompress creates a unique
     md#.uncompress device for each image.

     The geom_uncompress device is subsequently used by the FreeBSD kernel to access the disk images.  The geom_uncompress driver does not allow
     write operations to the underlying disk image.  To check which md(4) devices match a given geom_uncompress device:

	   # geom uncompress list
	   Geom name: md0.uncompress
	   Providers:
	   1. Name: md0.uncompress
	      Mediasize: 52428800 (50M)
	      Sectorsize: 512
	      Mode: r1w0e0
	   Consumers:
	   1. Name: md0
	      Mediasize: 20864000 (20M)
	      Sectorsize: 512
	      Mode: r1w0e0

SEE ALSO

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

AUTHORS

     The geom_uncompress driver was written by Maxim Sobolev <sobomax@FreeBSD.org> and Aleksandr Rybalko <ray@FreeBSD.org>.  This manual page was
     written by Luiz Otavio O Souza <loos@FreeBSD.org>.

BSD
								  January 9, 2014							       BSD

GMOUNTVER(8)						    BSD System Manager's Manual 					      GMOUNTVER(8)

NAME

     gmountver -- control utility for disk mount verification GEOM class

SYNOPSIS

     gmountver create [-v] dev ...
     gmountver destroy [-fv] prov ...
     gmountver list
     gmountver status [-s name]
     gmountver load [-v]
     gmountver unload [-v]

DESCRIPTION

     The gmountver utility is used to control the mount verification GEOM class.  When configured, it passes all the I/O requests to the underly-
     ing provider.  When the underlying provider disappears - for example because the disk device got disconnected - it queues all the I/O
     requests and waits for the provider to reappear.  When that happens, it attaches to it and sends the queued requests.

     The first argument to gmountver indicates an action to be performed:

     create   Cache the given devices with specified name.  The kernel module geom_mountver.ko will be loaded if it is not loaded already.

     destroy  Destroy name.

     list     See geom(8).

     status   See geom(8).

     load     See geom(8).

     unload   See geom(8).

     Additional options:

     -f      Force the removal of the specified mountver device.

     -v      Be more verbose.

SYSCTL VARIABLES

     The following sysctl(8) variables can be used to control the behavior of the MOUNTVER GEOM class.	The default value is shown next to each
     variable.

     kern.geom.mountver.debug: 0
	     Debug level of the MOUNTVER GEOM class.  This can be set to a number between 0 and 3 inclusive.  If set to 0 minimal debug informa-
	     tion is printed, and if set to 3 the maximum amount of debug information is printed.

     kern.geom.mountver.check_ident: 1
	     This can be set to 0 or 1.  If set to 0, gmountver will reattach to the device even if the device reports a different disk ID.

EXIT STATUS

     Exit status is 0 on success, and 1 if the command fails.

SEE ALSO

     geom(4), geom(8)

HISTORY

     The gmountver utility appeared in FreeBSD 9.0.

AUTHORS

     Edward Tomasz Napierala <trasz@FreeBSD.org>

BSD
								 January 27, 2015							       BSD