Administrator Guide

Table 2. RAID level comparison (continued)
RAID level Min. disks Description Strengths Weaknesses
performance is slower
than RAID 5
10
(1+0)
4 Stripes data across
multiple RAID-1
subgroups
Highest performance
and data protection
(protects against
multiple disk failures)
High redundancy cost
overhead: because all
data is duplicated,
twice the storage
capacity is required;
requires minimum of
four disks
50
(5+0)
6 Stripes data across
multiple RAID-5 sub-
groups
Better random read
and write performance
and data protection
than RAID 5; supports
more disks than RAID
5; protects against
multiple disk failures
Lower storage capacity
than RAID 5
ADAPT 12 Distributed erasure
coding with dual disk
failure protection
Very fast rebuilds, no
spare disks (built in
spare capacity), large
storage pools, simplified
initial deployment and
expansion
Requires minimum of 12
disks
Table 3. Number of disks per RAID level to optimize virtual disk group performance
RAID level Number of disks (data and parity)
1 2 total (no parity)
5 3 total (2 data disks, 1 parity disk); 5 total (4 data disks, 1
parity disk); 9 total (8 data disks, 1 parity disk)
6 4 total (2 data disks, 2 parity disks); 6 total (4 data disks, 2
parity disks); 10 total (8 data disks, 2 parity disks)
10 4–16 total
ADAPT 12–128 total
Table 4. Linear disk group expansion by RAID level
RAID level Expansion capability Maximum disks
NRAID Cannot expand. 1
0, 3, 5, 6 You can add from 1 to 4 disks at a time. 16
1 Cannot expand. 2
10 You can add 2 or 4 disks at a time. 16
50 You can add one sub-group at a time.
The added sub-group must contain the
same number of disks as each of the
existing sub-groups.
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ADAPT You can add up to 68 disks at a time. 128
About ADAPT
ADAPT is a RAID-based data protection level that maximizes flexibility, provides built in spare capacity, and allows for very fast
rebuilds, large storage pools, and simplified expansion. All disks in the ADAPT disk group must be the same type (enterprise
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Getting started