Ds3500 Iscsi Storage Configuration On Sles 11 Using Rdac; Preparing For The Installation - IBM System Storage DS3500 Introduction And Implementation Manual

Linux Config.fm
The virtual HBA driver creates virtual disks to represent the array LUNs, which the Linux OS
disk target driver "sd" will attach to. The array devices are then addressed through the virtual
host/LUN nodes. When an array/LUN has multiple possible paths with which it can be
accessed, the RDAC driver picks the correct path and routes I/O to it, performing any
necessary failover. This is transparent to the OS. This driver provides such capabilities as I/O
path load balancing and transparent failove r in the event of a path failure. The virtual HBA
driver also handles support in a server clustering environment, by translating SCSI-2
reservation/release commands to SCSI-3 persistent reservations.
UTM (Universal Transport Mechanism) LUNs are not represented as virtual disks. Thus the
RDAC driver does not create any special device nodes of its own for the UTM devices.
Instead, it allows the sg driver (the generic scsi driver on Linux) to claim the UTM physical
Luns, thus creating /dev/sg* entries, which can be discovered and used by the SMagent or
SANtricity UTM agent.
The following command shows a description of each parameter that the user may alter to
affect the RDAC execution.
# man rdac
The system-specific mechanism for reconfiguring the RDAC driver is the following:
1. Change the necessary parameters located in /etc/mpp.conf.
2. Run mppUpdate to build the new initrd images with the changes.
3. A driver reload or system reboot is necessary after the changes are made to the
configuration file
20.2 DS3500 iSCSI storage configuration on SLES 11 using
RDAC
In this section we discuss how to add a logical drive to an SLES 11 using DS3500 iSCSI
storage using RDAC multipath driver.

20.2.1 Preparing for the installation

For our setup, we used the following hardware and software components:
HS22 BladeServer.
Dual Port 1Gbps Ethernet HBA.
Two additional Ethernet switches for bladecenters
DS3500 Storage Subsystem
A management workstation running the latest version of DS Storage Manager.
The latest version IBM RDAC drivers for Linux.
SuSE Linux Enterprise 11
External ethernet switch
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IBM System Storage DS3500: Introduction and Implementation Guide
Draft Document for Review March 28, 2011 12:24 pm