HP XP P9500 Storage - Manual (Page 87)

Number of tiers in pool Tiering policy
selected with
performance graph
3 tiers 2 tiers 1 tier
You cannot select these settings
while displaying the performance You cannot select these
settings while displaying the Level 2
Level 3 graph. Use a setting of All
instead. performance graph. Use a
setting of All instead.
Level 4
In the performance graph, you
can display the frequency In the performance graph,
you can display the frequency Level 5
distribution of a THP V-VOL
assigned to level 5. distribution of a THP V-VOL
assigned to level 5.
Reserving tier capacity when setting a tiering policy
If you set a tiering policy on a THP V-VOL, the THP V-VOL allocated capacity and the estimated
I/O performance limits are reserved in the tier (see
“Example of reserving tier capacity” (page
87) ).
The reserved performance limit per page is calculated as follows:
performance-limit-per-page = total-esimated-performance-of-the-tier ÷
total-number-of-pages-in-the-tier
The THP V-VOLs to which a tiering policy is not set uses the unreserved tiering capacity in the pool.
For example, if the tiering policy for some THP V-VOLs is set to level 1, then the other THP V-VOLs
within that tiering policy can use the total areas of tier 2, tier 3, and the area of tier 1 that is not
reserved by level 1.
Example of reserving tier capacity
The following depicts reserving an area for tier capacity when changing the tiering policy setting
on a THP V-VOL.
Smart Tiers 87