HP XP P9500 Storage - Manual (Page 36)

5 Monitoring and maintenance
This topic provides monitoring, editing, and maintenance instructions for external volumes, paths,
and systems.
Monitoring external volumes and paths
You can view system details about mapped external volumes, the ports used, and the external
paths.
Procedure 5 To view mapped external volumes and paths
1. In Remote Web Console, click External Storages in the Storage Systems tree.
2. Select an external storage system.
3. Select a path group.
4. Select the Mapped Volumes tab.
5. Select an external volume row. Click External LUN Properties at the bottom of the window.
Editing external volume policies (settings)
When you map new external volumes, preset mapping policies are used. You can change default
mapping values without affecting settings in previously mapped volumes.
To reset the values for previously mapped volumes, go to the Edit External Volumes window and
change settings volume by volume.
The settings and their functions are described in the following bullets. To skip to the procedure,
see
Editing mapping policies (page 37) .
•
Base Emulation Type
Specify OPEN-V to use existing data in the external volume from HP P9500. ◦
◦ If you use an emulation type other than OPEN-V, the volume requires a specific area for
management data. This results in a volume capacity after mapping that is less than the
actual external volume capacity.
See Capacity requirements for volumes (page 16) for more information about capacity
and calculating the capacity of your external volume.
•
Cache Mode. I/O to and from the local storage system always uses cache. Write operations
are always backed up in duplex cache. The Cache Mode setting specifies whether write data
from the host is written to the external volume asynchronously (Enable) or synchronously
(Disable).
◦ If Enable is specified: After receiving the data into the local system’s cache memory, the
system signals the host that the I/O operation has completed and then asynchronously
destages the data to the external volume.
◦ When Disable is specified (the default): After synchronously writing the data to the external
volume, the local system signals the host that an I/O operation has completed.
For further discussion, see “Cache use and external storage performance” (page 14) .
•
Cache Partition. Cache memory can be partitioned using Cache Partition to configure a cache
logical partition (CLPR) for the mapped volumes. Cache logical partitions are often used to
limit cache-use by accessing slower external storage volumes.
HP strongly recommends that you place external storage array groups in a CLPR other than
CLPR0. See the HP XP P9000 Cache Partition User Guide for detailed information on CLPR.
36 Monitoring and maintenance