About this publication

Edit online

This white paper describes the basic configuration of Internet Small Computer Systems interface (iSCSI) initiator when Storwize® V7000 used as a iSCSI target. This white paper is written on the basis of SUSE Linux™ Enterprise 11 SP2 and Red Hat Enterprise Linux 6.4 results.

To provide a more complete picture of the configuration used in this white paper the iSCSI setup at Storwize V7000 is also briefly described.

The following IBM® storage products support iSCSI:

IBM Storwize V7000
IBM XIV® Storage System
IBM System Storage® DS5000 Series
IBM System Storage DS5020 Express®
IBM System Storage DCS3700
IBM Storwize V3700
IBM System Storage
DS3500 Express

Linux on System z® supports the following SCSI transports:

Fibre Channel Protocol (FCP), mapping of SCSI over Fibre Channel
iSCSI, mapping of SCSI over TCP/IP

FCP provides faster and more reliable access as compared to the iSCSI transport. But iSCSI is more cost effective than FCP.

Scope of this document

Advanced topics such as iSCSI multipath and iSCSI security are out of the scope of this document

Note: Although multipathing is not described in this document, it is strongly recommended for production environments.

Author

Deepak P Joshi

Linux on System z

Prerequisites

Red Hat Enterprise Linux 6 or SUSE Linux Enterprise Server 11 distribution installed on System z with the network configured. There must be connectivity between the Linux system and Storwize V7000. Linux on System z supports the following types of network connection:
- Network connections through Open Systems Adapter (OSA) - works in Layer-2 or Layer-3 mode
- HiperSockets
- GuestLAN
- Virtual Switch
Even though the above network connections are supported, the network connection must be configured through OSA either in Layer-2 or Layer-3 mode for the iSCSI configuration. In the z/VM® environment the Virtual Switch network connection with rdev option enabled can also be used for the iSCSI configuration.
HiperSockets™ and GuestLAN network connections cannot be used for the iSCSI configuration.
For more information about network connections with Linux on System z, see Device Drivers, Features and Commands:
- Reference for SUSE Linux Enterprise Server 11 SP2:
```
https://public.dhe.ibm.com/software/dw/linux390/docu/l26edd02.pdf?_gl=1*1b5k33e*_ga*MTg3ODM4ODA1Ny4xNjk1NzQwMzAy*_ga_FYECCCS21D*MTY5NTc5OTg5NC4yLjEuMTY5NTgwNjE2Ny4wLjAuMA..
```
- Reference for Red Hat Enterprise Linux 6.4:
```
https://public.dhe.ibm.com/software/dw/linux390/docu/lfu4dd04.pdf?_gl=1*te7y1o*_ga*MTg3ODM4ODA1Ny4xNjk1NzQwMzAy*_ga_FYECCCS21D*MTY5NTc5OTg5NC4yLjEuMTY5NTgwNjMzNS4wLjAuMA..
```
Storwize V7000 already configured with iSCSI LUNs and iSCSI target (iSCSI host object) created and mapped with iSCSI LUNs.
The IP address of the iSCSI portal and IQN of iSCSI target (iSCSI host object) at Storwize V7000

Restrictions

Storwize V7000 supports only one iSCSI session between an initiator and target at a time
There is no support for ipl'ng from Linux on system z