Arrays Across Loops; Storage System Logical Partitions; Ibm System Storage Resiliency Family - IBM DS8000 User Manual

Arrays across loops

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Storage system logical partitions

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IBM System Storage Resiliency Family

manage parity. However, with half of the DDMs in the group used for data and
the other half used to mirror that data, RAID 10 disk groups have less capacity
than RAID 5 disk groups.
The arrays across loops helps prevent data loss.
The storage unit provides arrays across loops. RAID 10 arrays across loops
provides mirroring across two loops, which prevents loss of the array during loop
failure. RAID 5 and RAID 6 arrays across loops provide a higher throughput to the
array because both loops on the device adapter are used in parallel. The main
difference between RAID 6 and the other supported arrays is the additional parity
DDM allocated to RAID 6.
The DS8300 Models 9A2 and 9B2 exploit logical partition (LPAR) technology,
allowing you to run two separate storage server images.
Each storage image has access to the following components:
50 percent of the processors is the default. With variable LPAR implementation
v
on DS8300 Model 9B2, the split can be 25/75 percent or 75/25 percent.
v 50 percent of the processors is the default. With variable LPAR implementation
on DS8300 Model 9B2, the split can be 25/75 percent or 75/25 percent.
v Up to 16 host adapters (4 I/O drawers with up to 4 host adapters).
v Up to 320 disk drives (up to 96 TB of capacity).
With these separate resources, each storage system LPAR can run the same or
different versions of microcode, and can be used for completely separate
production, test, or other unique storage environments within this single physical
system. Where separate storage subsystems were previously required, this
capability enables storage consolidation, which increases management efficiency
and cost effectiveness.
Typically, the different machine code levels of a common release are compatible.
However, certain levels of licensed machine code might not be compatible if the
later licensed machine code level contains substantial enhancements. If your levels
of licensed machine code are not compatible, you can contact IBM support to
request instructions for installing the two different licensed machine code levels. In
addition, if each logical partition runs a different level of machine code, you can
contact IBM support to request a code level upgrade on either partition. Your
requests will be evaluated and approved based on your particular configuration.
IBM System Storage Resiliency Family is a set of products and features that can
help you implement storage solutions to keep your business running 24 hours a
day, 7 days a week. This set of products provides disaster recovery, data migration,
and data duplication functions.
As a part of the IBM System Storage Resiliency Family, the DS8000 series supports
Copy Service functions that contribute to the protection of your data. These
functions are also supported on the IBM TotalStorage Enterprise Storage Server.
Chapter 1. Introduction to IBM System Storage DS8000 series
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