IBM Storwize V7000, Введение и руководство по внедрению

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Chapter 8. Storage pools
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2. Click Next and select an appropriate RAID preset (Figure 8-17) and click Next.
Figure 8-17 Select a RAID preset
3. Select the Number of drives to provision in the configuration. By default, all drives with
the
Candidate
status are included, and drives with the
Unused
status are made available
for use in the array as well. Also, the wizard offers to automatically configure spares to
match the spare goal, as explained in “RAID configuration presets” on page 322. Disabling
this option enables you to define spare drives manually by marking drives with the status
Candidate
as
Spare
. You then must decide to use one of the two optimization options:
– Optimize for Performance:
The goal of this algorithm is to create arrays with identical capacity and performance
characteristics to achieve the best possible performance for the volumes to be created.
In a performance optimized setup, IBM Flex System V7000 Storage Node provisions
eight physical disk drives in a single array MDisk, except for the following situations:
• RAID 6 uses 12 disk drives.
• SSD Easy Tier uses two disk drives.
Hence, creating an
Optimized for Performance
configuration is only possible if
sufficient number of drives available to match your needs.
As a consequence, all arrays with similar physical disks feature the same performance
characteristics. Due to the defined presets, this setup might leave drives unused. The
remaining unconfigured drives can be used then in another array.