Veritas Storage Foundation Intelligent Storage Provisioning 5.0.1 Administrators Guide, HP-UX 11i v3, First Edition, November 2009
enclosures,” and using the set of heuristic rules that were hard-coded within
vxassist.
Although some storage attributes are known to VxVM, you must do most of the
work in deciding how to lay out the storage if you are to create a volume with the
desired performance, reliability and fault tolerance.
Figure 1-1 shows the traditional model for allocating storage to volumes.
Figure 1-1
Traditional model for creating and administering volumes in Veritas
Volume Manager
Storage within a disk group
Volumes are built from the
available storage
according to hard-coded
rules, and as explicitly
specified by you.
User specifications
for volume layout
Attributes
vxassist
Volumes
The vxassist command
uses hard-coded rules to
create and administer
volumes. You can
override these rules by
stating explicitly which
storage is to be used.
Knowledge of storage attributes
in VxVM is limited to
automatically discovered
information such as enclosure
membership, and path and
controller connectivity. Beyond
this, you must state explicitly
which storage to use.
When intelligent disk arrays are used, many sophisticated features, such as RAID
capabilities, snapshot facilities, and remote replication, are provided by logical
unit storage devices, LUNs, that are exported by the disk array. Such devices may
or may not have ways of making their attributes known to VxVM. In any case,
you may be presented with hundreds or thousands of LUNs connected over a SAN.
Allocating storage to volumes when faced with a potentially large number of
devices with widely varying and possibly hidden properties is a daunting task to
19Understanding ISP
The benefits of ISP