Assigned Cms; Stable Operation Via Load Control; Quality Of Service (Qos); Figure 63 Assigned Cms - Fujitsu ETERNUS AF250 Design Manual

1. Function

Stable Operation via Load Control

Assigned CMs

A controller that controls access is assigned to each RAID group and manages the load balance in the ETERNUS
AF. The controller that controls a RAID group is called an assigned CM.

Figure 63 Assigned CMs

Switch
CM#0
Assigned
CM
RAID group #0
RAID group #2
ETERNUS AF
When the load is unbalanced between the controllers, change the assigned CM.
If an assigned controller is disconnected for any reason, the assigned CM is replaced by another controller. After
the disconnected controller is installed again and returns to normal status, this controller becomes the assigned
CM again.
Stable Operation via Load Control

Quality of Service (QoS)

●
QoS
The performance of a high priority server is guaranteed by configuring the performance limit of each connected
server.
When the load from one application is high in a storage integrated environment and sufficient resources to
process other operations cannot be secured, performance may be reduced.
The QoS function guarantees performance by limiting resources for applications with a low priority so that re-
sources are secured for high priority applications.
16 priority levels of bandwidth limits (maximum performance limits) can be configured on the hosts, CA ports,
volumes, and LUN groups. The performance configuration patterns of the bandwidth limit can be individually
changed via ETERNUS CLI.
In addition, scheduled operations (when setting a bandwidth limit for hosts, CA ports, and LUN groups) are pos-
sible by setting a duration using ETERNUS CLI.
The assigned CM of the RAID
Switch
CM#1
Assigned
CM
RAID group #1
FUJITSU Storage ETERNUS AF250 S2, ETERNUS AF250 All-Flash Arrays Design Guide (Basic)
Copyright 2019 FUJITSU LIMITED
group controls access
102
P3AG-1822-09ENZ0