No matter what disks you have, there are always potential problems:
They can be too small.
They can be too slow.
They can be too unreliable.
One way some users safeguard themselves against such issues is through the use of multiple, and sometimes redundant, disks.
In addition to supporting various cards and controllers for hardware RAID systems, the base FreeBSD system includes the Vinum Volume Manager, a block device driver that implements virtual disk drives.
Vinum provides more flexibility, performance, and reliability than traditional disk storage, and implements RAID-0, RAID-1, and RAID-5 models both individually and in combination.
This chapter provides an overview of potential problems with traditional disk storage, and an introduction to the Vinum Volume Manager.
Starting with FreeBSD 5, Vinum has been rewritten in
order to fit into the GEOM architecture (Rozdział 18, GEOM: Modular Disk Transformation Framework),
retaining the original ideas, terminology, and on-disk metadata.
This rewrite is called gvinum (for
GEOM vinum). The following text usually refers to
Vinum as an abstract name, regardless of the
implementation variant. Any command invocations should now be
done using the gvinum command, and the name of
the kernel module has been changed from
vinum.ko to
geom_vinum.ko, and all device nodes reside
under /dev/gvinum instead of
/dev/vinum. As of FreeBSD 6, the old Vinum
implementation is no longer available in the code
base.
All FreeBSD documents are available for download at https://download.freebsd.org/ftp/doc/
Questions that are not answered by the
documentation may be
sent to <freebsd-questions@FreeBSD.org>.
Send questions about this document to <freebsd-doc@FreeBSD.org>.