Accusys ExaSAN A12S2-PS - Manual (Page 60)

4. How to Use
User Guide Page 4-9
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 Description Capacity
RAID 0 Striping, the fastest and most
efficient array type but offers no
fault-tolerance
Total of all drives
RAID 1 Mirroring, All disks have the same
data
Total of one drive
RAID 5 Block-level striping with distributed
parity, one disk fault tolerant
Total of all drives minus one
drive
RAID 6 Block-level striping with double
distributed parity, two disks fault
tolerant
Total of all drives minus two
drives
RAID 0+1 Combines the advantage of R0
and R1, provides optimal speed
and reliability
One-half the total capacity of
drives (Sum of RAID 1 member
sets)
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:
DAS Example 2:
DAS Example 3: