IBM DS8700, Introduction And Planning Manual

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Easy Tier: manual mode
Easy Tier in manual mode provides the capability to migrate volumes and merge
extent pools, under the same DS8700 and DS8800 system, concurrently with I/O
operations.
In Easy Tier manual mode, you can dynamically relocate a logical volume between
extent pools or within an extent pool to change the extent allocation method of the
volume or to redistribute the volume across new ranks that have been added. This
capability is referred to as
dynamic volume relocation . You can also merge two
existing pools into one without affecting the data on the logical volumes associated
with the extent pools.
Enhanced functions of Easy Tier manual mode offer additional capabilities. You
can use manual mode to relocate your extents, or to relocate an entire volume from
one pool to another pool. Later, you might also need to change your storage media
or configurations. Upgrading to a new disk drive technology, rearranging the
storage space, or changing storage distribution within a given workload are typical
operations that you can perform with volume relocations. Use manual mode to
achieve these operations with minimal performance impact and to increase the
options you have in managing your storage.
Highest
Performance
Tier
SSD
RANK 1
SSD
RANK 2
SSD
RANK n
. . .
ENT HDD
RANK 1
. . .
ENT HDD
RANK 2
ENT HDD
RANK n
Higher
Performance
Tier
NLHDD RANK
1
NLHDD RANK
2
NLHDD RANK
m
. . .
Lower
Performance
Tier
Expanded
Cold Demote
Cold
Demote
Swap
Warm
Demote
Promote
Swap
Auto
Rebalance
Auto
Rebalance
f2c01682
Warm
Demote
Promote
Figure 13. Three-tier migration types and their processes
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Introduction and Planning Guide