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gconcatdisk

GCONCAT(8) System Manager's Manual GCONCAT(8)

NAME

gconcatdisk concatenation control utility

SYNOPSIS

gconcat create [-v] name prov ...

gconcat destroy [-fv] name ...

gconcat label [-hv] name prov ...

gconcat stop [-fv] name ...

gconcat clear [-v] prov ...

gconcat dump prov ...

gconcat list

gconcat status

gconcat load

gconcat unload

DESCRIPTION

The gconcat utility is used for device concatenation configuration. The concatenation can be configured using two different methods: “manual” or “automatic”. When using the “manual” method, no metadata are stored on the devices, so the concatenated device has to be configured by hand every time it is needed. The “automatic” method uses on-disk metadata to detect devices. Once devices are labeled, they will be automatically detected and configured.
The first argument to gconcat indicates an action to be performed:
create
Concatenate the given devices with specified name. This is the “manual” method. The kernel module geom_concat.ko will be loaded if it is not loaded already.
label
Concatenate the given devices with the specified name. This is the “automatic” method, where metadata are stored in every device's last sector. The kernel module geom_concat.ko will be loaded if it is not loaded already.
stop
Turn off existing concatenate device by its name. This command does not touch on-disk metadata!
destroy
Same as stop.
clear
Clear metadata on the given devices.
dump
Dump metadata stored on the given devices.
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 concatenated device.
-h
Hardcode providers' names in metadata.
-v
Be more verbose.

SYSCTL VARIABLES

The following sysctl(8) variables can be used to control the behavior of the CONCAT GEOM class. The default value is shown next to each variable.
kern.geom.concat.debug: 0
Debug level of the CONCAT GEOM class. This can be set to a number between 0 and 3 inclusive. If set to 0 minimal debug information is printed, and if set to 3 the maximum amount of debug information is printed.

EXIT STATUS

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

EXAMPLES

The following example shows how to configure four disks for automatic concatenation, create a file system on it, and mount it:
gconcat label -v data /dev/da0 /dev/da1 /dev/da2 /dev/da3 
newfs /dev/concat/data 
mount /dev/concat/data /mnt 
[...] 
umount /mnt 
gconcat stop data 
gconcat unload
Configure concatenated provider on one disk only. Create file system. Add two more disks and extend existing file system.
gconcat label data /dev/da0 
newfs /dev/concat/data 
gconcat label data /dev/da0 /dev/da1 /dev/da2 
growfs /dev/concat/data

SEE ALSO

geom(4), loader.conf(5), geom(8), growfs(8), gvinum(8), mount(8), newfs(8), sysctl(8), umount(8)

HISTORY

The gconcat utility appeared in FreeBSD 5.3.

AUTHORS

Pawel Jakub Dawidek ⟨pjd@FreeBSD.org⟩
May 21, 2004 Debian Sid