Dell EqualLogic PS4100E, Руководство по настройке, Страница: 71 / 152

March 2013 Dell EqualLogic Configuration Guide v14.1 7-62
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Any EqualLogic SAN group that is required to send or receive replication traffic to/from another
SAN group must have an uninterrupted communications path (ie. “visibility”) between each group.
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To prevent a switch failure from also disabling all paths between a host and its connected
volumes, all ports from each controller need to be connected to at least two different switches
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For PS4100/PS6100 family arrays, split the vertical port pair connections between two switches to
ensure 100% bandwidth capability is maintained in the event of a vertical port failover event. See
the configuration diagrams in Section 7.3.6.
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The above guideline regarding path redundancy across multiple switches also applies in FS Series
NAS appliance configurations. (Refer to the connection diagrams in Section 13.1)
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Do not block IPv6 traffic on the SAN internal switches when utilizing FS Applicances
FS76x0 uses IPv6 for internal communication and setup only; not for user data.
Client communication happens over IPv4
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For SANs connecting to an FS Series appliance, all switches in the SAN must have jumbo frames
enabled.
For EqualLogic PS Series Arrays, the following general SAN design recommendations apply:
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Take advantage of your switch’s VLAN capabilities. You should create a VLAN dedicated to iSCSI
traffic (even on dedicated switches). If necessary, create a second VLAN for management traffic.
The actual VLAN configuration of your iSCSI SAN will be dictated by your SAN network design
requirements and the features of the iSCSI SAN switches being used.
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Jumbo frames should be enabled. If you choose to use jumbo frames then all nodes in the SAN
fabric must have jumbo frames enabled.
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For best performance and reliability, we recommend that all interconnection paths between non-
stacking switches (LAGs) use a dynamic link aggregation protocol such as LACP
7.1.3 Quality of service (qos)
Quality of service is described as either of the following:
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The ability to provide different priority levels to different applications, users, or data flows, or to
guarantee a certain level of performance to a data flow.
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A network function implemented in some routers and switches that provides high priority for
certain types of latency-sensitive traffic (for example, VoIP) and lower priority for other types of
traffic (for example, web or http).
PS Series arrays are designed to provide I/O as fast as your network can support it. Therefore, using
QoS with iSCSI traffic does not produce expected or desirable results on the SAN. Also, QoS rules can
affect how well–or even whether–replication succeeds between PS Series groups. If you plan to use
QoS, Dell recommends that you use it only on VLANs that do not carry iSCSI traffic, or on WANs,
where bandwidth is shared with other applications and the PS Series array uses it for time-insensitive
replication traffic.
Dell recommends against using QoS on the SAN.
7.2 Ethernet switches and infrastructure
Any switch used in an EqualLogic SAN should meet the requirements listed in this section.