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 and as SNMP traps to the open-systems host.
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 161)
for more details.
The Protect attribute is applied to the THP V-VOL and is used in conjunction with other HP 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 Data
Retention,
Not Permitted
appears in the
S-VOL
field in the Data Retention window.
Monitoring performance
You can monitor system performance using Performance Monitor. For more information, see the
HP XP7 Performance for Open and Mainframe Systems User Guide.
You can monitor information on pools and THP V-VOLs using RAID Manager. For more information,
see the HP XP7 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
pool allocation rates). You can then use this monitor information to tune the appropriate
allocation.
◦
Access frequency of THP V-VOL, read hit rates, and write hit rates (using Performance
Monitor)
◦
Usage rates of property groups of pools (using Performance Monitor)
◦
Pool usage and elapsed time of pool usage (using Remote Web Console).
Monitoring capacity and performance
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