HP XP P9500 Storage - Manual (Page 124)

Monitoring capacity and performance
Monitoring pool capacity
The storage system monitors the pool’s free capacity in accordance with threshold values defined
when you create pools. If the pool capacity reaches the threshold values, warnings are issued as
SIMs to Remote Web Console and SNMP traps to the open-systems host. See
“Monitoring pool
usage levels” (page 124) for more information.
You can provision a larger virtual capacity beyond the pool capacity by using THP V-VOLs of Thin
Provisioning or Smart Tiers. However, when the pool’s free capacity is depleted, you can lose
access to THP V-VOLs that require more pool capacity. For example, if the pool usage rate is 100%
due to increased write operations, then I/O is not accepted and I/O will be stopped for a THP
V-VOL that failed to receive needed pool capacity. Therefore, you should carefully monitor the
pool usage or pool free capacity, as well as the level of provisioned virtual capacity.
Protecting data during pool shortages
To protect data from reading and writing to the THP V-VOL when the pool is full, you can apply
access attributes to a volume. To do this, you need to enable the use of the Data Retention, by
insuring the license is installed and using system option mode 729. This protection method applies
a Protect attribute to the THP V-VOL to protect volumes against write operations when the pool is
full. See
“Assigning an access attribute to a volume” (page 145) for more details.
The Protect attribute is applied to the THP V-VOL and is used in conjunction with other Hitachi
software products. When the Protect attribute is applied to the THP V-VOL, Permitted appears in
the S-VOL field and 0 day appears in the Validation field of the Data Retention window. However,
when the Protect attribute is added to the THP V-VOL with the S-VOL unacceptable attribute available
in the Hitachi Data Retention Utility, Not Permitted appears in the S-VOL field in the Data Retention
window.
Monitoring pool usage levels
Several tools are available that show both the current pool usage rates and the changes over time
for those usage rates. These tools help you monitor the pool free space and estimate when you
will need to increase the pool capacity by adding pool volumes.
In Storage Navigator the Pool window, use the Virtual Volumes tab to view THP V-VOL usage rates
and pool usage rates (see
“Pools window after selecting pool (Pools window)” (page 277) and
( “Top window when selecting a pool under Pools” (page 282) .
If you have Command View Advanced Edition, you can monitor THP V-VOL usage and pool usages
rates using the time-variable graph.
Monitoring performance
You can monitor system performance using Performance Monitor (see the HP P9000 Performance
for Open and Mainframe Systems User Guide). You can monitor information on pools and THP
V-VOLs using RAID Manager (RAID Manager) (see HP P9000 RAID Manager User Guide).
The following activities help you to monitor and control performance of the THP V-VOL. Collecting
monitor information and subsequent tuning may increase throughput and the operating rates.
•
Collecting monitor information. Collecting the following monitor information helps you determine
the pool load (including the access frequency, the trend of pool usage rates, and the access
load upon data drives) and THP V-VOL load (including the access frequency and the trend of
124 Configuring thin provisioning