HP 3PAR InForm OS 3.1.1 CLI Administrator's Manual

Viewing Histograms for Chunklets
NOTE: The setstatch command must be issued to enable statistics collection on chunklets
before chunklet histogram data can be viewed.
• To view histogram data for chunklets, issue the histch command.
Several filters are provided to refine the data output to display only data from specific chunklets
and logical disks. Additional filters are provided to customize the way the histogram data is
displayed. Refer to the InForm OS Command Line Reference for complete details about histch
command options and for sample command data output.
Viewing Histograms for Logical Disks
• To view histogram data for logical disks, issue the histld command.
The histld command provides filters to refine the data output to display only data from
logical disks mapped to specific virtual volumes. Additional filters are provided to customize
the way the histogram data is displayed. Refer to the InForm OS Command Line Reference
for complete details about histld command options and for sample command data output.
Viewing Histograms for Physical Disks
• To view histogram data for physical disks, issue the histpd command.
Histogram data output can be further refined to display physical disk data from:
◦ a specific physical disk by either its ID or WWN.
◦ specific nodes.
◦ specific PCI slots.
◦ specific ports.
You can use additional filters to customize the way the histogram data is displayed. Refer to
the InForm OS Command Line Reference for complete details about histpd command options
and for sample command data output.
NOTE: The Device Speed number does not represent a rotational speed for Solid State Drives
(SSD) without spinning media. It is meant as a rough estimation of the performance difference
between the drive and the other drives in the system. For FC and NL drives, the number corresponds
to both a performance measure and actual rotational speed. For an SSD, the number is to be
treated as a relative performance benchmark that takes into account I/O per second, bandwidth,
and the access time.
Viewing Histograms 121