Iscsi Multipath Connectivity - IBM V7000 Introduction And Implementation Manual

The following points apply to multisession configuration:
The AIX iSCSI initiator does not support multisession.
The use of the supported iSCSI multipathing is recommended when running the I/O with
multisession.
If you use CHAP authentication under the Microsoft Windows operating system, use the
same secret across each session that is initiated from that host to a particular target.
If the Microsoft Windows clustered system is rebuilt or restored from a backup, hosts must
log off and then log back on to any previously connected iSCSI targets that are supplied
from the system.
If the host application uses SCSI 3 Persistent Reservation, you must run only a single
iSCSI session.
Running with multiple iSCSI sessions is not supported for applications using Microsoft
2003 MSCS and Microsoft 2008 Failover clustering over an iSCSI interface; you must run
only a single session in these situations.

11.3.4 iSCSI multipath connectivity

You can choose from several technologies to improve the availability of iSCSI by using
multiple network paths. Multipathing requires a software layer above the iSCSI layer to make
sense of the multiple physical paths between the initiator and target and to manage them
appropriately.
Within the IBM Flex System Enterprise Chassis I/O modules 1+2 will be populated by
Ethernet switches, these will allow iSCSI connectivity between a compute node and IBM Flex
System V7000 Storage Node. It is important to configure for switch redundancy by using
iSCSI multipathing device driver software on the compute node host operating system. At the
IBM Flex System V7000 Storage Node canisters, both iSCSI Ethernet ports should be used.
In Figure 11-1 on page 460, it can be seen that NW 1 on each node canister is connected to
Switch 1 and Switch 2. When configuring for iSCSI connectivity as shown here in Figure 11-5,
port 2 is represented by the link to Switch 1, and port 3 is represented by the link to Switch 2
across both canisters.
Figure 11-5 iSCSI ports 2 and 3 linking to switches in IBM Flex System Enterprise Chassis
Chapter 11. SAN connections and configuration
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