Cisco AP775A - Nexus Converged Network Switch 5010 User Manual

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50-51
Cisco MDS 9000 Family Fabric Manager Configuration Guide
OL-17256-03, Cisco MDS NX-OS Release 4.x
Chapter 50 Configuring iSCSI
iSCSI High Availability
Figure 50-36 Host Running Multi-Path Software
Each IPS ports is exporting the same two Fibre Channel target ports of the storage but as different iSCSI
target names if you use dynamic iSCSI targets). So the two IPS ports are exporting a total of four iSCSI
target devices. These four iSCSI targets map the same two ports of the Fibre Channel target.
The iSCSI host uses NIC-1 to connect to IPS port 1 and NIC-2 to connect to IPS port 2. Each IPS port
exports two iSCSI targets, so the iSCSI host creates four iSCSI sessions.
If the iSCSI host NIC-1 fails (see Figure 50-36 for the physical view), then sessions 1 and 2 fail but we
still have sessions 3 and 4.
If the IPS port 1 fails, the iSCSI host cannot connect to the IPS port, and sessions 1 and 2 fail. But
sessions 3 and 4 are still available.
If the storage port 1 fails, then the IPS ports will terminate sessions 1 and 3 (put iSCSI virtual target
iqn.com.cisco.mds-5.1-2.p1 and iqn-com.cisco.mds-5.1-1.p1 in offline state). But sessions 2 and 4 are
still available.
In this topology, you have recovery from failure of any of the components. The host multi-path software
takes care of load-balancing or failover across the different paths to access the storage.
iSCSI HA with Host Not Having Any Multi-Path Software
The above topology will not work if the host does not have multi-path software because the host has
multiple sessions to the same storage. Without multi-path software the host does not have knowledge of
the multiple paths to the same storage.
iSCSIiSCSI
IP 10.1.1.1/24
10.1.1.2/24
iSCSIiSCSI
IP 20.1.1.1/24
21.1.1.1/24
P1
P2
Ethernet
switch
IP Network
1/1
2/1
MDS
Switch
MDS 1
Storage
Logical View
IP Network
Session 1
Session 2
Session 3
Session 4
iSCSIiSCSI
iSCSIiSCSI
H2
H1
iqn.com.cisco.mds-1.1-1.P1
iqn.com.cisco.mds-
1.1-1.P2
iqn.com.cisco.mds-
1.1-1.P2
P1
P2
P2
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Cisco AP775A - Nexus Converged Network Switch 5010 Specifications

General

Brand	Cisco
Model	AP775A - Nexus Converged Network Switch 5010
Category	Switch
Language	English