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# 22.8 Configuring Vinum

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.

## 22.8.1 Startup

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.

### 22.8.1.1 Automatic Startup

Gvinum always features an automatic startup once the kernel module is loaded, via loader.conf(5). To load the Gvinum module at boot time, add `geom_vinum_load="YES"` to `/boot/loader.conf`.

When you start Vinum with the `gvinum 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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