HP MSA 1040 SMU Reference Guide (762784-001, March 2014)

System concepts 27
NOTE: To create an NRAID, RAID-0, or RAID-3 vdisk, you must use the CLI create vdisk command. For more
information on this command, see the CLI Reference Guide.
Table 3 Example applications and RAID levels
Application RAID level
Testing multiple operating systems or software development (where redundancy is not an issue) NRAID
Fast temporary storage or scratch disks for graphics, page layout, and image rendering 0
Workgroup servers 1 or 10
Video editing and production 3
Network operating system, databases, high availability applications, workgroup servers 5
Very large databases, web server, video on demand 50
Mission-critical environments that demand high availability and use large sequential workloads 6
Table 4 RAID level comparison
RAID
level
Min.
disks
Description Strengths Weaknesses
NRAID 1 Non-RAID, nonstriped
mapping to a single disk
Ability to use a single disk to store
additional data
Not protected, lower performance
(not striped)
0 2 Data striping without
redundancy
Highest performance No data protection: if one disk
fails all data is lost
1 2 Disk mirroring Very high performance and data
protection; minimal penalty on
write performance; protects
against single disk failure
High redundancy cost overhead:
because all data is duplicated,
twice the storage capacity is
required
3 3 Block-level data striping
with dedicated parity
disk
Excellent performance for large,
sequential data requests (fast
read); protects against single disk
failure
Not well-suited for
transaction-oriented network
applications; write performance is
lower on short writes (less than 1
stripe)
5 3 Block-level data striping
with distributed parity
Best cost/performance for
transaction-oriented networks;
very high performance and data
protection; supports multiple
simultaneous reads and writes;
can also be optimized for large,
sequential requests; protects
against single disk failure
Write performance is slower than
RAID 0 or RAID 1
6 4 Block-level data striping
with double distributed
parity
Best suited for large sequential
workloads; non-sequential read
and sequential read/write
performance is comparable to
RAID 5; protects against dual disk
failure
Higher redundancy cost than
RAID 5 because the parity
overhead is twice that of RAID 5;
not well-suited for
transaction-oriented network
applications; non-sequential write
performance is slower than RAID
5