IBM DS8700, Введение и руководство по планированию

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You can also use Easy Tier in automatic mode to assist in the management of your
ESE thin provisioning on fixed block (FB) volumes.
Easy Tier feature enhancements help you to effectively manage your system health,
storage performance, and storage capacity automatically. Easy Tier uses system
configuration and workload analysis with warm demotion to achieve effective
overall system health. Simultaneously, data promotion and auto-rebalancing
address performance while cold demotion works to address capacity. This
maximizes performance while minimizing cost. See “Easy Tier: automatic mode”
on page 44 for more information.
An additional enhancement provides the capability for you to use Easy Tier in
manual mode for thin provisioning. Rank depopulation is supported on ranks with
ESE volumes allocated (extent space-efficient) or auxiliary volumes. See “Easy Tier:
manual mode” on page 48 for more information.
Note: Use Easy Tier in manual mode to depopulate ranks containing TSE auxiliary
volumes.
Use the capabilities of Easy Tier to support:
v Three tiers - Using three tiers and enhanced algorithms improves system
performance and cost effectiveness.
v
Cold demotion - Cold data (or extents) stored on a higher-performance tier is
demoted to a more appropriate tier. Easy Tier is available with two-tier HDD
pools as well as with three-tier pools. Sequential bandwidth is moved to the
lower tier to increase the efficient use of your tiers. For more information on
cold demote functions, see “Easy Tier: automatic mode” on page 44.
v
Warm demotion - Active data that has larger bandwidth is demoted from either
tier one (SSD) or tier two (Enterprise) to SAS Enterprise or Nearline SAS on the
DS8800 (FC or SATA on a DS8700) to appropriate storage tiers to help protect
drive performance. Warm demotion is triggered whenever the higher tier is over
its bandwidth capacity. Selected warm extents are demoted to allow the higher
tier to operate at its optimal load. Warm demotes do not follow a predetermined
schedule. For more information on warm demote functions, see “Easy Tier:
automatic mode” on page 44.
v
Manual volume or pool rebalance - Volume rebalancing relocates the smallest
number of extents of a volume and restripes those extents on all available ranks
of the extent pool.
v Auto-rebalancing - Automatically balances the workload of the same storage tier
within both the homogeneous and the hybrid pool based on usage to improve
system performance and resource use. Use the enhanced auto-rebalancing
functions of Easy Tier to manage a combination of homogenous and hybrid
pools, including relocating hot spots on ranks. With homogenous pools, systems
with only one tier can use Easy Tier technology to optimize their raid array
utilization.
v
Rank depopulations - Allows ranks that have extents (data) allocated to them to
be unassigned from an extent pool by using extent migration to move extents
from the specified ranks to other ranks within the pool.
v
Thin provisioning - Support for the use of thin provisioning is available on ESE
(FB) and standard volumes. The use of TSE volumes (FB and CKD) is not
supported.
Easy Tier provides a performance monitoring capability, regardless of whether the
Easy Tier license feature is activated. Easy Tier uses the monitoring process to
Chapter 3. Data management features
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