As described above, Vinum assigns default names to plexes and subdisks, although they may be overridden. Overriding the default names is not recommended: experience with the VERITAS volume manager, which allows arbitrary naming of objects, has shown that this flexibility does not bring a significant advantage, and it can cause confusion.
Names may contain any non-blank character, but it is recommended to restrict them to letters, digits and the underscore characters. The names of volumes, plexes and subdisks may be up to 64 characters long, and the names of drives may be up to 32 characters long.
Vinum objects are assigned device nodes in the hierarchy
/dev/gvinum
. The configuration shown above
would cause Vinum to create the following device nodes:
This only applies to the historic Vinum implemenation.
The control devices
/dev/vinum/control
and
/dev/vinum/controld
, which are used
by gvinum(8) and the Vinum daemon respectively.
Device entries for each volume.
These are the main devices used by Vinum. Thus the configuration
above would include the devices
/dev/gvinum/myvol
,
/dev/gvinum/mirror
,
/dev/gvinum/striped
,
/dev/gvinum/raid5
and
/dev/gvinum/raid10
.
This only applies to the historic Vinum implemenation.
A directory /dev/vinum/drive
with entries for each drive. These entries are in fact
symbolic links to the corresponding disk nodes.
All volumes get direct entries under
/dev/gvinum/
.
The directories
/dev/gvinum/plex
, and
/dev/gvinum/sd
, which contain
device nodes for each plex and for each subdisk,
respectively.
For example, consider the following configuration file:
After processing this file, gvinum(8) creates the following
structure in /dev/gvinum
:
Although it is recommended that plexes and subdisks should not be allocated specific names, Vinum drives must be named. This makes it possible to move a drive to a different location and still recognize it automatically. Drive names may be up to 32 characters long.
Volumes appear to the system to be identical to disks,
with one exception. Unlike UNIX® drives, Vinum does
not partition volumes, which thus do not contain a partition
table. This has required modification to some disk
utilities, notably newfs(8), which previously tried to
interpret the last letter of a Vinum volume name as a
partition identifier. For example, a disk drive may have a
name like /dev/ad0a
or
/dev/da2h
. These names represent
the first partition (a
) on the
first (0) IDE disk (ad
) and the
eighth partition (h
) on the third
(2) SCSI disk (da
) respectively.
By contrast, a Vinum volume might be called
/dev/gvinum/concat
, a name which has
no relationship with a partition name.
Normally, newfs(8) interprets the name of the disk and complains if it cannot understand it. For example:
#
newfs /dev/gvinum/concat
newfs: /dev/gvinum/concat: can't figure out file system partitionIn order to create a file system on this volume, use newfs(8):
#
newfs /dev/gvinum/concat
On FreeBSD versions prior to 5.0 newfs(8) requires an additional -v flag and the old device naming scheme:
#
newfs -v /dev/vinum/concat
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