Example of reserving tier capacity
The reservation priority depends on the level of tiering policy. The following figure illustrates the
reservation priority. Tiers are reserved in order of priority from (1) to (7) in the figure. If the pool-VOL
capacity is deficient when you reserve a tier, the nearest tier of your specified tier is allocated. If
you specify two tiers like level 2 or level 4 of the tiering policy, first of all the upper tier is reserved.
At this time, if the capacity of the pool-VOL assigned to the upper tier is deficient, the lower tier
defined by the tiering policy is reserved automatically. For example, in case of level 2 in the
diagram below, tier 1 is reserved first. If the capacity of tier 1 is deficient at this point, tier 2 is
reserved automatically. For details, see
“Notes on tiering policy settings” (page 103)
.
Reserved tier
Tiering policy
Tier reservation
priority
Tier 1
Level1(1)
1
Tier 2
Level3(3)
2
Tier 3
Level5(5)
3
102 Configuring thin provisioning