HP XP7 PA Software User Guide

Determining disk space requirements
Use the following formula to determine the disk space requirements for HP XP7 Performance Advisor
on a day basis. The factors that influence the output are the number of arrays, LDEVs, ports, DKC
components, performance data collection, and collection frequency:
Free_Space (MB/day for one array) = [(SECONDS_PER_DAY /
Ldev_Collection_frequency) * LDEVs * Ldev_Space ] + [(SECONDS_PER_DAY
/ Port_Collection_ frequency) * PORTs * Port_Space] + [(SECONDS_PER_DAY/
Dkc_Collection_ frequency) * Dkc_Space]
where:
• Free_Space (MB/day) = Total free disk space (in MB) required for a day
• LDEVs = Total number of LDEVs in an XP or an XP7 disk array (includes journal volumes, pool
volumes, external volumes, and so on)
• PORTs = Total number of ports for an XP or an XP7 disk array
• Ldev_Collection_frequency = Collection frequency for LDEVs (in seconds)
• Port_Collection_frequency = Collection frequency for ports (in seconds)
• Dkc_Collection_ frequency = Collection frequency for DKC (in seconds)
• Ldev_Space (per Ldev) = 0.0002 MB
• Port_Space (per port) = 0.00008 MB
• Dkc_Space (per collection) = 0.0002 MB
• SECONDS_PER_DAY = 86400
The consolidated free space that is available for HP XP7 Performance Advisor is the total sum
of the free space available on all the XP and the XP7 disk arrays monitored by HP XP7
Performance Advisor.
170 Managing the HP XP7 Performance Advisor database