Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

221Creating and administering plexes
Attaching and associating plexes
DETACHED plex kernel state
Maintenance is being performed on the plex. Any write request to the volume is not
reflected in the plex. A read request from the volume is not satisfied from the plex. Plex
operations and ioctl function calls are accepted.
DISABLED plex kernel state
The plex is offline and cannot be accessed.
ENABLED plex kernel state
The plex is online. A write request to the volume is reflected in the plex. A read request
from the volume is satisfied from the plex. If a plex is sparse, this is indicated by the
SPARSE modifier being displayed in the output from the
vxprint -t command.
Attaching and associating plexes
A plex becomes a participating plex for a volume by attaching it to a volume. (Attaching a
plex associates it with the volume and enables the plex for use.) To attach a plex to an
existing volume, use the following command:
# vxplex [-g diskgroup] att volume plex
For example, to attach a plex named vol01-02 to a volume named vol01 in the disk
group, mydg, use the following command:
# vxplex -g mydg att vol01 vol01-02
If the volume does not already exist, a plex (or multiple plexes) can be associated with the
volume when it is created using the following command:
# vxmake [-g diskgroup] -U usetype vol volume plex=plex1[,plex2...]
For example, to create a mirrored, fsgen-type volume named home, and to associate
two existing plexes named home-1 and home-2 with home, use the following
command:
# vxmake -g mydg -U fsgen vol home plex=home-1,home-2
Note: You can also use the command vxassist mirror volume to add a data plex as
a mirror to an existing volume.
Taking plexes offline
Once a volume has been created and placed online (ENABLED), VxVM can temporarily
disconnect plexes from the volume. This is useful, for example, when the hardware on
which the plex resides needs repair or when a volume has been left unstartable and a
source plex for the volume revive must be chosen manually.