McDATA 8832 warranty Rdac Installation and Configuration, Serial Over LAN SOL for Blades, Overview

IBM BladeCenter Deployment Guide

If you are installing SLES9 to a local drive on an HS20, watch out for this RETAIN tip: http://www- 1.ibm.com/support/docview.wss?uid=psg1MIGR-57841.

4.7 RDAC Installation and Configuration

Notes on Linux

There are two versions of the Linux RDAC. The version (09.00.A5.09)for Linux 2.4 kernels only like Redhat EL 3 and SuSe SLES 8 and RDAC package version 09.01.B5.XX for Linux 2.6 kernel environment.

•Make sure you read the README.TXT files for V9.15 Linux RDAC, HBA and Storage Manager for Linux.

•When using the Linux RDAC as the failover/failback driver, the host type should be set to LNXCL instead of Linux. If Linux RDAC is not used, the host type of Linux must be used instead.

•There is not a requirement that the UTM (Access LUN) must be removed from the LNXCL Storage Partitioning partition.

•The Linux RDAC driver cannot co-exist with a HBA-level multi-path failover/failback driver such as the 6.06.63-fo driver. You might have to modify the driver make file for it to be compiled in the non- failover mode.

•Auto Logical Drive Transfer (ADT/AVT) mode is not supported when using Linux in a cluster, or when using RDAC. Since ADT(AVT) is automatically enabled in the Linux storage partitioning host type. It has to be disabled by selecting 'host type' of LNXCL.

•AVT is required if you are using the Qlogic Failover drivers.

•The Linux SCSI layer does not support skipped (sparse) LUNs. If the mapped LUNs are not contiguous, the Linux kernel will not scan the rest of the LUNs. Therefore, the LUNs after the skipped LUN will not be available to the host server. The LUNs should always be mapped using consecutive LUN numbers

•Although the host server can have different FC HBAs from multiple vendors or different FC HBA models from the same vendors, only one model of FC HBAs can be connected to the IBM DS4000 Storage Servers.

•If a host server has multiple HBA ports and each HBA port sees both controllers (via an un-zoned switch), the Linux RDAC driver may return I/O errors during controller failover.

•Linux SCSI device names have the possibility of changing when the host system reboots. We recommend using a utility such as devlabel to create user-defined device names that will map devices based on a unique identifier, called a UUID. The devlabel utility is available as part of the Red Hat Enterprise Linux 3 distribution, or online at: http://www.lerhaupt.com/devlabel/devlabel.html

•Linux RDAC supports re-scanning to recognize a newly mapped LUN without rebooting the server. The utility program is packed with the Linux RDAC driver. It can be invoked by using either hot_add or mppBusRescan command (note that hot_add is a symbolic link to mppBusRescan). There are man pages for both commands. However, the Linux RDAC driver doesn't support LUN deletion. One has to reboot the server after deleting the mapped logical drives

4.8Serial Over LAN (SOL) for Blades

4.8.1 Overview

The Management Module command-line interface provides access to the text-console command prompt on each blade server through a Serial over LAN (SOL) connection, enabling the blade servers to be managed from a remote location.

To start an SOL connection with a blade server, you must first start a telnet or ssh session with the management module. When this session is running, you can start a remote-console SOL session with any blade server in the BladeCenter unit that is set up and enabled for SOL operation. You can establish up to 20 separate Telnet sessions with a BladeCenter management module. For a BladeCenter unit, this enables you to have 14 simultaneous SOL sessions active (one for each of up to 14 blade servers) with 6 additional command-line interface sessions available for BladeCenter unit management.

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The BladeCenter Deployment Guide is intended as a personal productivity tool. It is not intended to be comprehensive and is provided for

guidance only, on an 'as is basis' without warranty of any kind. Please be aware that its contents have not been certified by IBM.