Administrator Guide

Table Of Contents
Best practices
This appendix describes best practices for configuring and provisioning a storage system.
Topics:
Pool setup
RAID selection
Disk count per RAID level
Disk groups in a pool
Tier setup
Multipath configuration
Physical port selection
Pool setup
In a storage system with two controller modules, try to balance the workload of the controllers. Each controller can own
one virtual pool. Having the same number of disk groups and volumes in each pool will help balance the workload, increasing
performance.
RAID selection
A pool is created by adding disk groups to it. Disk groups are based on RAID technology.
The following table describes the characteristics and use cases of each RAID level:
RAID level
Protection Performance Capacity Application use
cases
Suggested disk
speed
RAID 1/RAID 10
Protects against up
to one disk failure
per mirror set
Great random I/O
performance
Poor: 50% fault
tolerance capacity
loss
Databases, OLTP,
Exchange Server
10K, 15K, 7K
RAID 5 Protects against up
to one disk failure
per RAID set
Good sequential
I/O performance,
moderate random
I/O performance
Great: One-disk
fault tolerance
capacity loss
Big data, media
and entertainment
(ingest, broadcast,
and past
production)
10K, 15K, lower
capacity 7K
RAID 6 Protects against up
to two disk failures
per RAID set
Moderate
sequential I/O
performance, poor
random I/O
performance
Moderate: Twodisk
fault tolerance
capacity loss
Archive, parallel
distributed file
system
High capacity 7K
Disk count per RAID level
The controller breaks virtual volumes into 4-MB pages, which are referenced paged tables in memory. The 4-MB page is a fixed
unit of allocation. Therefore, 4-MB units of data are pushed to a disk group. A write performance penalty is introduced in RAID-5
or RAID-6 disk groups when the stripe size of the disk group isn't a multiple of the 4-MB page.
Example 1: Consider a RAID-5 disk group with five disks. The equivalent of four disks provide usable capacity, and the
equivalent of one disk is used for parity. Parity is distributed among disks. The four disks providing usable capacity are the
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