HP LeftHand P4000 SAN Solutions - Manual (Page 158)

Table 51 Characteristics for new volumes (continued)
Definition Configurable
for Primary
or Remote
volume Volume
characteristic
Both Type • Primary volumes are used for data storage.
•
Remote volumes are targets for Remote Copy snapshots. These snapshots are used for a
variety of purposes such as business continuance, disaster recovery, as well as data
migration and data analysis.
The default value is Primary.
Primary Provisioning •
Fully provisioned volumes are the same size on the cluster as the size presented to the
application server.
• Thinly provisioned volumes have less space reserved on the cluster than the size presented
to the application server. As data is stored on the volume, the LeftHand OS software
automatically increases the amount of space allocated on the cluster.
The default value is Full for the following data protection levels.
•
Network RAID-0 (None)
•
Network RAID-10 (2–Way Mirror)
• Network RAID-10+1 (3–Way Mirror)
•
Network RAID-10+2 (4–Way Mirror)
The default value is Thin for the following data protection levels.
• Network RAID-5 (Single Parity)
•
Network RAID-6 (Dual Parity)
Thin provisioning is the best practice configuration for Network RAID-5 and Network RAID-6
volumes, and all other volumes which have, or will have, a larger number of snapshots. This
configuration ensures better capacity utilization.
NOTE: The LeftHand OS software allocates space as needed. However, thin provisioning
carries the risk that, if all warnings are ignored, an application server will fail a write because
the SAN has run out of disk space.
When creating primary volumes, the default value for Adaptive Optimization is Permitted.
However, only volumes that are in clusters containing Adaptive Optimization-capable storage
systems can make use of Adaptive Optimization. Primary Adaptive
Optimization
Leaving the Adaptive Optimization value as Permitted on volumes in clusters that do not
contain Adaptive Optimization-capable storage systems does not affect the volume or the
cluster. HP recommends leaving the setting as Permitted unless you are certain that the volume
should never participate in Adaptive Optimization.
In a mixed cluster that contains Adaptive Optimization-capable storage systems and
non-Adaptive Optimization-capable storage systems, you may not achieve the expected
performance improvements.
Viewing the volume map
After you create volumes and finish setting up the SAN, use the Map View tab for viewing the
relationships between volumes, snapshots, servers, and remote copies. For more information on
using the map view tools, see
“Using the display tools” (page 10) .
Editing a volume
Edit a primary volume to change the description, size, and advanced characteristics such as data
protection level, type, provisioning, Adaptive Optimization settings, and the cluster (migrating or
moving the volume).
NOTE: Moving the volume to a different cluster requires restriping the data in both clusters.
Depending on volume sizes and workload on the cluster, restriping can take hours, or even days.
158 Using volumes