Front cover Linux for IBM System z9 and IBM zSeries Running Linux on IBM System z9 and IBM zSeries Using and configuring the Linux 2.6 kernel Virtualizing with z/VM Gregory Geiselhart Robert Brenneman Eli Dow Klaus Egeler Torsten Gutenberger Bruce Hayden Livio Sousa ibm.com/redbooks International Technical Support Organization Linux for IBM System z9 and IBM zSeries January 2006 SG24-6694-00 Note: Before using this information and the product it supports, read the information in “Notices” on page vii. First Edition (January 2006) This edition applies to Version 5, Release 1 of z/VM and multiple distributions of Linux for zSeries based on the 2.6 Linux kernel. © Copyright International Business Machines Corporation 2006. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Notices . vii Trademarks . viii Preface . ix The team that wrote this redbook. ix Become a published author . x Comments welcome. xi Chapter 1. Introduction to z/Architecture . 1 1.1 The zSeries and System z9 servers . 2 1.2 The central processing complex . 2 1.2.1 Processing units . 2 1.3 The channel subsystem . 2 1.4 Logical partition concepts . 4 1.4.1 LPAR dispatching . 4 Chapter 2. Linux 2.6 kernel. 9 2.1 Choosing a 64-bit or 31-bit Linux distribution . 10 2.1.1 Linux 31-bit compatibility mode. 10 2.2 Performance and scalability enhancements . 11 2.2.1 The new Linux process scheduler. 12 2.2.2 System swap setting . 13 2.2.3 Kernel preemption. 13 2.2.4 Fast user-space mutual exclusion . 13 2.2.5 I/O performance and scalability enhancements . 14 2.2.6 I/O schedulers . 14 2.2.7 Extended attributes and access control lists . 16 2.2.8 Memory management enhancements. 17 2.2.9 Native POSIX Threading Library. 17 2.2.10 NFS version 4 . 19 2.3 Introduction to sysfs . 20 2.3.1 Organization of the /sys directory . 20 2.3.2 New sysfs command for Linux on zSeries . 22 2.3.3 Device configuration with sysfs . 24 2.3.4 SLES9 hardware configuration . 24 2.3.5 RHEL4 hardware configuration . 28 2.3.6 Device node naming with udev . 32 2.3.7 Hotplug detection and device node naming . 33 2.3.8 Distribution considerations when naming devices . 36 © Copyright IBM Corp. 2006. All rights reserved. iii 2.4 S/390 tools and utilities . 37 2.4.1 The cmsfslst command . 38 2.4.2 The tunedasd command . 38 2.4.3 The dasdview command . 39 Chapter 3. Virtualization with z/VM . 41 3.1 z/VM and virtualization . 42 3.1.1 z/VM guest support . 42 3.2 Installing z/VM 5.1 . 43 3.2.1 Installation to FCP-attached SCSI disk . 43 3.3 Distributions for Linux on zSeries . 47 3.3.1 SUSE Linux Enterprise Server 9. 47 3.3.2 Red Hat Enterprise Linux 4 . 47 3.3.3 Non-commercial distributions . 48 3.3.4 IBM middleware for Linux on zSeries . 48 3.4 Running Linux under z/VM . 49 3.4.1 Managing guest virtual memory . 49 3.4.2 Managing z/VM storage . 49 3.4.3 Managing the VM scheduler . 53 3.4.4 Performance monitoring . 56 Chapter 4. Networking Overview . 59 4.1 Networking options . 60 4.2 Physical networking options . 60 4.2.1 Open Systems Adapter-2 (OSA-2) . 60 4.2.2 Open Systems Adapter-Express (OSA-Express) . 60 4.2.3 Channel-to-channel adapter . 76 4.2.4 Common Link Access to Workstation (CLAW) . 82 4.3 HiperSockets . 83 4.4 Virtualization technology . 91 4.5 Point-to-point connectivity . 91 4.5.1 Guest LAN. 93 4.6 Guest LAN configuration . 96 4.6.1 Create a z/VM Guest LAN. 96 4.6.2 Persistent Guest LANs . 97 4.6.3 The VMLAN statement . 98 4.6.4 Create a virtual Network Interface Card . 100 4.6.5 NIC definition in the user directory . 100 4.6.6 NIC definition using CP commands . 102 4.6.7 Connect the virtual NIC to the Guest LAN . 103 4.6.8 Example of building a z/VM Guest LAN . 104 4.6.9 Undoing the definitions . 106 4.6.10 Configuring Linux to connect to a Guest LAN . 107 iv Linux for IBM System z9 and IBM zSeries 4.7 Virtual Switch. 108 4.8 Introduction to VLANs . 109 4.8.1 What is a Virtual LAN . 109 4.8.2 VLAN standards . 113 4.8.3 How IEEE 802.1Q VLANs work . 114 4.8.4 VLAN support on z/VM Guest LAN . 119 4.8.5 VLANs on z/VM Virtual Switch . 119 4.8.6 VLAN isolation. 120 4.9 VSWITCH configuration . 121 4.9.1 Transport mode: IP or Ethernet. 121 4.9.2 Configure controller service machines . 121 4.9.3 Defining a VSWITCH . 124 4.9.4 VSWITCH failover support . 126 4.10 Layer 2 test scenario . ..