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 traditional 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 drives 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.