Iscsi Security; Stable Operation Via Load Control; Quality Of Service (Qos); Figure 72 Qos - Fujitsu ETERNUS DX500 S4/DX600 S4 Design Manual

3. SAN Functions

Stable Operation via Load Control

iSCSI Security

For an iSCSI interface, the iSCSI authentication function can be used when the initiator accesses the target. The
iSCSI authentication function is available for host connections and remote copying.
The Challenge Handshake Authentication Protocol (CHAP) is supported for iSCSI authentication. For CHAP Au-
thentication, unidirectional CHAP or bidirectional CHAP can be selected. When unidirectional CHAP is used, the
target authenticates the initiator to prevent fraudulent access. When bidirectional CHAP is used, the target au-
thenticates the initiator to prevent fraudulent access and the initiator authenticates the target to prevent imper-
sonation.
Note that the Internet Storage Name Service (iSNS) is also supported as an iSCSI name resolution.
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.
Linking with ETERNUS SF Storage Cruiser significantly reduces the operation workload on the system administra-
tor when applying the QoS function because performance designing and tuning are automatically performed.

Figure 72 QoS

Server A Server B
Low priority High priority
ETERNUS DX
FUJITSU Storage ETERNUS DX500 S4/DX600 S4, ETERNUS DX500 S3/DX600 S3 Hybrid Storage Systems Design Guide (Basic)
When QoS is not applied
Processing requests
from A increase
Server A
Required performance for A
Affects the performance of B
Server B
Required performance for B
I/O performance
Because the workload for A, which has a low
priority, significantly increases, the required
performance for B cannot be maintained
122
Copyright 2019 FUJITSU LIMITED
When QoS is applied
The workload does not exceed
the upper limit even when
Server A
processing requests from A
increase
Workload upper limit for A
Server B
High
I/O performance
Because the workload for A is lower than
the upper limit, the workload for B, which has
a high priority, can be reduced
Workload upper limit for B
High
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