Table of Contents
Advertisement
Storage Pool Capacity
When allocating raw storage to pools, keep in mind that filling pools completely will result in
significantly reduced performance, especially when writing to shares or LUNs. These effects
become more noticeable as the pool reaches full capacity.
Data Profiles for Storage Pools
After storage devices are physically verified and resources are allocated for a storage pool,
the next step is to choose a storage profile that reflects your reliability, availability and
serviceability (RAS), and performance goals. The set of possible profiles presented depends on
your available storage. The following table lists all possible profiles and their descriptions.
Data Profiles
TABLE 20
Data Profile
Dual Parity Options
Triple mirrored
Double parity RAID
Single Parity Options
Mirrored
Single parity RAID, narrow stripes
Viewing Pool and Device Status (BUI)
Description
Data is triply mirrored, yielding a very highly reliable
and high-performing system (for example, storage
for a critical database). This configuration is intended
for situations in which maximum performance and
availability are required. Compared with a two-way
mirror, a three-way mirror adds additional IOPS per
stored block and higher level protection against failures.
Note: A controller without expansion storage should not
be configured with triple mirroring.
RAID in which each stripe contains two parity disks.
As with triple mirroring, this yields high availability, as
data remains available with the failure of any two disks.
Double parity RAID is a higher capacity option than
the mirroring options and is intended either for high-
throughput sequential-access workloads (such as backup)
or for storing large amounts of data with low random-
read component.
Data is mirrored, reducing capacity by half, but
yielding a highly reliable and high-performing system.
Recommended when space is considered ample, but
performance is at a premium (for example, database
storage).
RAID in which each stripe is kept to three data disks
and a single parity disk. For situations in which single
parity protection is acceptable, single parity RAID offers
a much higher capacity option than simple mirroring.
This higher capacity needs to be balanced against a
Configuring the Appliance
111
Advertisement
Table of Contents
