IBM DS8700, Введение и руководство по планированию

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determine what data to move and when to move it when using automatic mode.
You can enable monitoring independently (with or without the Easy Tier license
feature activated) for information about the behavior and benefits that can be
expected if automatic mode were enabled. For more information, see “Monitoring
volume data” on page 51.
Data from the monitoring process is included in a summary report that you can
download to your Windows system. Use the IBM System Storage DS8000 Storage
Tier Advisor Tool application to view the data when you point your browser to
that file. For more information, see “IBM System Storage DS8000 Storage Tier
Advisor Tool” on page 52.
Prerequisites
The following conditions must be met to enable Easy Tier:
v The Easy Tier license feature is enabled (required for both manual and automatic
mode, except when monitoring is set to All Volumes).
v
For automatic mode to be active, the following conditions must be met:
– Easy Tier automatic mode monitoring is set to either All or Auto mode.
– For Easy Tier to manage pools, the Auto Mode Volumes must be set to either
Tiered Pools or All Pools.
Table 6 contains drive combinations you can use with your three-tier configuration,
and with the migration of your ESE volumes, for DS8700 and DS8800.
Table 6. Drive combinations to use with three-tiers
Models Drive combinations: three tiers
DS8700 SSD, FC, and SATA
DS8800 SSD, SAS Enterprise, Nearline SAS
Notes:
1. Easy Tier features include extendable support in automatic mode for FC (enterprise
class) and SATA storage tiers.
2. SATA drives are not available for DS8800 in SAS 2, 2.5” form factor.
3.
For version 6, release 2 and later, the top tier in a three-tier configuration can only be
SSD.
Easy Tier: automatic mode
Use of the automatic mode of Easy Tier requires the Easy Tier license feature.
In Easy Tier, both IOPS and bandwidth algorithms determine when to migrate
your data. This process can help you improve performance.
Use automatic mode to have Easy Tier relocate your extents to their most
appropriate storage tier in a hybrid pool, based on usage. Because workloads
typically concentrate I/O operations (data access) on only a subset of the extents
within a volume or LUN, automatic mode identifies the subset of your frequently
accessed extents and relocates them to the higher-performance storage tier.
Subvolume or sub-LUN data movement is an important option to consider in
volume movement because not all data at the volume or LUN level becomes hot
data. For any given workload, there is a distribution of data considered either hot
or cold. This can result in significant overhead associated with moving entire
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Introduction and Planning Guide