Table 20 Cabling principles (Brick balance in strings)
Cabling principle
Applicability
A string may contain up to eight Bricks. (FC Expansion Bricks
(version 1) are not included in this number).
ALL
When additional Bricks are added or when SSF performance
issues occur, it may be necessary to rearrange the Bricks
between strings to better balance the system.
NEW
Bricks in a Pillar Axiom 600 system can follow a heuristic balance
or a numerical balance defined by manufacturing practices.
ALL
A numerical balance allocates Bricks to strings uniformly without
regard to the type of Brick. The longest and shortest Brick strings
differ by at most one Brick, with the exception of FC Expansion
Bricks.
NEW
Some rules have been developed to achieve a heuristic balance
on Brick strings. The heuristic balance on Brick strings helps to
optimize performance on larger systems with mixed Brick types.
Brick strings are balanced on the basis of load factors allocated to
the different Brick types as follows:
● SATA Brick: Load factor 1
● FC RAID Brick: Load factor 2
● SSD Brick: Load factor 4
Version 1 and version 2 of all Brick types are allocated the same
load factor.
Note: The recommendation to not mix SATA Bricks (version 1)
with other Brick types overrides load factor considerations on
Brick strings.
FIELD
Table 21: Cabling principles (Brick adds on strings)
defines the procedures to be
followed when adding Bricks on Brick strings within a Pillar Axiom 600 system.
Table 21 Cabling principles (Brick adds on strings)
Cabling principle
Applicability
Bricks may be added to a Pillar Axiom 600 system without
disrupting client data availability. However, considerable care
must be taken while performing non-disruptive Brick adds. If there
FIELD
Chapter 4 Connect Data Cables
Cabling Practices for the Pillar Axiom 600 System
101
