New page assignment tier – HP XP P9500 Storage User Manual
Page 101
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For level 4, when tier 2 is full, the pages are allocated to tier 3. If tier 3 is full, the pages
are allocated to tier 1.
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For level 5, when tier 3 is full, the pages are allocated to tier 2. If tier 2 is full, the
unallocated pages are allocated to tier 1.
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If I/Os occur that exceed the I/O performance of the tier:
If the tiering level on the THP V-VOL is set to all tiers, the tier range is considered and the
tier capacity and the limit performance are allocated.
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However, if the tiering policy level on the THP V-VOL is set to a specific tier, the tier range
is considered and only the tier capacity is allocated. In this case, if I/O loads exceed the
assumed value, the tier to which a tiering level is set may degrade I/O performance.
Consider the I/O loads when you configure the tiers.
New page assignment tier
If you set the new page assignment tier value, when a new page is needed by a THP V-VOL the
page is taken from the specified tier aligned with the new page assignment tier value. You can
set this function by using Remote Web Console. In addition, this function becomes effective just
after setting. The following table lists setting values:
Description
Setting value
The new page is assigned from the higher tier of tiers set in the tiering policy.
High
The new page is assigned from the middle tier of tiers set in the tiering policy.
Middle
The new page is assigned from the lower tier of tiers set in the tiering policy.
Low
The following tables show the tiers to which new pages are preferentially assigned.
Note
When specifying Low
When specifying
Middle
When specifying High
Tiering level of the
tiering policy
If you set Low, tier 2 is given
a priority over tier 1.
From tier 2 to 1
From tier 1 to 2
From tier 1 to 2
All
Assignment sequences when
High, Middle, and Low are
same.
From tier 1 to 2
From tier 1 to 2
From tier 1 to 2
Level 1
Every assignment sequence
is the same as when All is
specified as the tiering level.
From tier 2 to 1
From tier 1 to 2
From tier 1 to 2
Level 2
Every assignment sequence
is the same as when All is
specified as the tiering level.
From tier 2 to 1
From tier 1 to 2
From tier 1 to 2
Level 3
Every assignment sequence
is the same as when All is
specified as the tiering level.
From tier 2 to 1
From tier 1 to 2
From tier 1 to 2
Level 4
Assignment sequences when
High, Middle, and Low are
same.
From tier 2 to 1
From tier 2 to 1
From tier 2 to 1
Level 5
Smart Tiers
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