The GENERIC
kernel does not contain
Vinum. It is possible to build a special kernel which includes
Vinum, but this is not recommended. The standard way to start
Vinum is as a kernel module (kld). You do
not even need to use kldload(8) for Vinum: when you start
gvinum(8), it checks whether the module has been loaded, and
if it is not, it loads it automatically.
Vinum stores configuration information on the disk slices in essentially the same form as in the configuration files. When reading from the configuration database, Vinum recognizes a number of keywords which are not allowed in the configuration files. For example, a disk configuration might contain the following text:
volume myvol state up volume bigraid state down plex name myvol.p0 state up org concat vol myvol plex name myvol.p1 state up org concat vol myvol plex name myvol.p2 state init org striped 512b vol myvol plex name bigraid.p0 state initializing org raid5 512b vol bigraid sd name myvol.p0.s0 drive a plex myvol.p0 state up len 1048576b driveoffset 265b plexoffset 0b sd name myvol.p0.s1 drive b plex myvol.p0 state up len 1048576b driveoffset 265b plexoffset 1048576b sd name myvol.p1.s0 drive c plex myvol.p1 state up len 1048576b driveoffset 265b plexoffset 0b sd name myvol.p1.s1 drive d plex myvol.p1 state up len 1048576b driveoffset 265b plexoffset 1048576b sd name myvol.p2.s0 drive a plex myvol.p2 state init len 524288b driveoffset 1048841b plexoffset 0b sd name myvol.p2.s1 drive b plex myvol.p2 state init len 524288b driveoffset 1048841b plexoffset 524288b sd name myvol.p2.s2 drive c plex myvol.p2 state init len 524288b driveoffset 1048841b plexoffset 1048576b sd name myvol.p2.s3 drive d plex myvol.p2 state init len 524288b driveoffset 1048841b plexoffset 1572864b sd name bigraid.p0.s0 drive a plex bigraid.p0 state initializing len 4194304b driveoff set 1573129b plexoffset 0b sd name bigraid.p0.s1 drive b plex bigraid.p0 state initializing len 4194304b driveoff set 1573129b plexoffset 4194304b sd name bigraid.p0.s2 drive c plex bigraid.p0 state initializing len 4194304b driveoff set 1573129b plexoffset 8388608b sd name bigraid.p0.s3 drive d plex bigraid.p0 state initializing len 4194304b driveoff set 1573129b plexoffset 12582912b sd name bigraid.p0.s4 drive e plex bigraid.p0 state initializing len 4194304b driveoff set 1573129b plexoffset 16777216b
The obvious differences here are the presence of explicit location information and naming (both of which are also allowed, but discouraged, for use by the user) and the information on the states (which are not available to the user). Vinum does not store information about drives in the configuration information: it finds the drives by scanning the configured disk drives for partitions with a Vinum label. This enables Vinum to identify drives correctly even if they have been assigned different UNIX® drive IDs.
This information only relates to the historic Vinum implementation. Gvinum always features an automatic startup once the kernel module is loaded.
In order to start Vinum automatically when you boot the
system, ensure that you have the following line in your
/etc/rc.conf
:
start_vinum="YES" # set to YES to start vinum
If you do not have a file
/etc/rc.conf
, create one with this
content. This will cause the system to load the Vinum
kld at startup, and to start any objects
mentioned in the configuration. This is done before
mounting file systems, so it is possible to automatically
fsck(8) and mount file systems on Vinum volumes.
When you start Vinum with the vinum
start
command, Vinum reads the configuration
database from one of the Vinum drives. Under normal
circumstances, each drive contains an identical copy of the
configuration database, so it does not matter which drive is
read. After a crash, however, Vinum must determine which
drive was updated most recently and read the configuration
from this drive. It then updates the configuration if
necessary from progressively older drives.
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