Planning Your Raid - Accusys ExaSAN A08S3-PS User Manual

4.1.2.2 Planning your RAID

Before using RAIDGuard X to set up your RAID storage, it is a good idea to become familiar
with the variety of configurations, or schemes, that are available for the ExaSAN RAID storage.
This section describes these schemes and illustrates how each RAID level is applied.
RAID Level
RAID 0
RAID 1
RAID 5
RAID 6
RAID 0+1
When configuring RAID, you may take the follow items into consideration:
1. Are you using a DAS or SAN environment?
2. Do you currently have more than one RAID or JBOD?
3. Which is more important, transfer speed or data security? One or two disk fault tolerance?
4. Do you need multiple volume or single volume on your RAID systems?
5. Do you have to consider the metadata volume for SAN software?
6. Do you consider using Global spare drives?
7. The number of disk drives used determines the speed of the RAID created. Take into
account the desired speed when configuring RAID.
DAS Example 1:
Figure 40: Create array with 8 HDDs in RAID 5
DAS Example 2:
Figure 41: Create array with 8 HDDs in RAID 6
User Guide
Description
Striping, the fastest and most
efficient array type but offers no fault-
tolerance
Mirroring, All disks have the same
data
Block-level striping with distributed
parity, one disk fault tolerant
Block-level striping with double
distributed parity, two disks fault
tolerant
Combines the advantage of R0 and
R1, provides optimal speed and
reliability
Capacity
Total of all drives
Total of one drive
Total of all drives minus one drive
Total of all drives minus two
drives
One-half the total capacity of
drives (Sum of RAID 1 member
sets)
4. How to Use
Page 4-9