You must follow these configuration guidelines and procedures for your
storage system to maximize performance
and to avoid potential I/O problems.
General guidelines
You must follow these general guidelines when you configure your storage systems.
Avoid splitting
arrays into multiple logical disks at the storage system level. Where possible,
create a single logical disk from the entire capacity of the array.
You can intermix different block-size drives within an array and a
storage pool. However, performance degradation can occur if you intermix 512 block-size drives and
4096 block-size drives within an array.
Depending on
the redundancy that is required, create RAID-5 (RAID 5) arrays by using 5 - 8 data bits plus parity
components (that is, 5 + P, 6 + P, 7 + P or 8 + P).
Do not mix
managed disks (MDisks) that greatly vary in performance in the same storage pool tier. The overall
storage pool performance in a tier is limited by the slowest MDisk. Because some storage systems can
sustain much higher I/O bandwidths than others, do not mix MDisks that are provided by low-end storage systems with MDisks that are
provided by high-end storage systems in
the same tier. You must consider the following factors:
The underlying RAID type that the storage system is using to implement the
MDisk.
The number of physical disks in the array (for example, 10,0000 or 15,0000 RPM) and the physical
disk type (for example, Fibre Channel or SATA).
When possible, include similarly sized MDisks in a storage pool tier to make it easier to
balance the MDisks in the storage pool tier. If the MDisks in a storage pool tier are significantly
different sizes, you can balance the proportion of space that is allocated on each MDisk by
including the larger MDisk multiple times in the MDisk list. This configuration is specified when
you create a new volume. For example, if you have two 400 MB disks and one 800 MB disk that are
identified as MDisk 0, 1, and 2, you can create the striped volume with the MDisk IDs of 0:1:2:2.
This configuration doubles the number of extents on the 800 MB drive, which accommodates it being
double the size of the other MDisks.
Complete the appropriate calculations to ensure that your storage systems are configured
correctly.
If any storage
system that is associated with an MDisk has the allowquorum parameter set to
no, the chquorum command fails for that MDisk.
Before you set the allowquorum parameter to yes on
any storage system, check the following website for storage system configuration requirements:
Logical disk configuration guidelines for storage systems
Most storage systems provide some mechanism to create multiple logical disks from a single array. This mechanism is useful when the storage system presents storage directly to the hosts.
Optimal storage pool configuration guidelines for storage systems A storage pool provides the pool of storage from which volumes are created. For optimal performance and reliability, you must ensure that the MDisks that make up each tier of the storage pool have the same characteristics.