IBM AIX Continuous Availability Features - IBM Redbooks

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compression: on path specification: on corefile location: /coredumps naming specification: off In Example 2-7 on page 35, we have created a file system to store core files generated on the local system. This file system is mounted in the /coredumps directory. Next we created a core file for a program (sleep 5000), as shown in Example 2-8. We send the program to the background, so we get the process id, then we kill the program with Abort (-6) flag, and observe the core file. Example 2-8 Core file example 2.4 Network tools lpar15root:/root#sleep 5000 & [1] 397486 lpar15root:/root#kill -6 397486 lpar15root:/root# [1] + IOT/Abort trap(coredump) sleep 5000 & lpar15root:/root#ls -l /coredumps total 16 -rw------- 1 root system 7188 Oct 27 07:16 core.397486.27121636 drwxr-xr-x 2 root system 256 Oct 27 07:07 lost+found lpar15root:/root#lquerypv -h /coredumps/core.397486.27121636 6b0 64 000006B0 7FFFFFFF FFFFFFFF 7FFFFFFF FFFFFFFF |................| 000006C0 00000000 00000FA0 7FFFFFFF FFFFFFFF |................| 000006D0 00120000 28E1D420 00000000 00000003 |....(.. ........| 000006E0 736C6565 70000000 00000000 00000000 |sleep...........| 000006F0 00000000 00000000 00000000 00000000 |................| 00000700 00000000 00000000 00000000 0000002B |...............+| 00000710 00000000 00000001 00000000 0000002B |...............+| Networking is the means for a user to access system resources, application and data. Without network connectivity, the system is practically unavailable. AIX ensures maximum and efficient network performance and system availability to meet user needs by controlling computing resources in order to minimize network problems and facilitate system administration procedures. This section covers the following network-related utilities currently available in AIX: ► Virtual IP address support ► Multipath IP routing ► Dead gateway detection ► EtherChannel ► IEEE 802.3ad Link Aggregation ► 2-Port Adapter-based Ethernet Failover ► Shared Ethernet Failover Additional details and configuration information on these topics can be found in AIX 5L Differences Guide Version 5.2 Edition, SG24-5765, AIX 5L Differences Guide Version 5.3 Edition, SG24-7463, and IBM AIX Version 6.1 Differences Guide, SC27-7559. 36 IBM AIX Continuous Availability Features
2.4.1 Virtual IP address support (VIPA) Prior to AIX V5.1, separate applications were required to provide high availability for a service IP address and its associated interface. If the network interface failed, then the application’s TPCP/IP session was often lost, resulting in the loss of application availability. To overcome this, support for virtual IP addresses (VIPA) on both IPv4 and IPv6 was introduced in AIX V5.1. VIPA allows the application to bind to a system-wide level virtual IP address, as opposed to a single network interface. VIPA is a virtual device often utilizing several network interfaces. VIPA can often mask underlying network interface failures by re-routing automatically to a different one. This allows continued connectivity and is transparent to the application and processes. VIPA also supports load balancing of traffic across the available connections. Another advantage of choosing a virtual device (as opposed to defining aliases to real network interfaces) is that a virtual device can be brought up or down separately without having any effect on the real interfaces of a system. Furthermore, it is not possible to change the address of an alias (aliases can only be added and deleted), but the address of a virtual interface can be changed at any time. Since its initial introduction in AIX V5.1, VIPA has been enhanced to make it friendlier, from a network administration perspective. It has also been enhanced so that failovers are completed faster, thus further improving availability. 2.4.2 Multipath IP routing Prior to AIX V5.1, a new route could be added to the routing table only if it was different from the existing routes. The new route would have to be different by either destination, netmask, or group ID. Also, previous AIX releases did not provide any mechanism to associate a specific interface with a route. When there were multiple interfaces on the same subnet, the same outgoing interface for all destinations accessible through that network was always chosen. In order to configure a system for network traffic load balancing, it is desirable to have multiple routes so that the network subsystem routes network traffic to the same network segment by using different interfaces. With the new multipath routing feature in AIX V6.1, routes no longer need to have a different destination, netmask, or group ID list. If there are several routes that equally qualify as a route to a destination, AIX will use a cyclic multiplexing mechanism (round-robin) to choose between them. The benefit of this feature is two-fold: ► It enables load balancing between two or more gateways. ► The feasibility of load balancing between two or more interfaces on the same network can be realized. The administrator would simply add several routes to the local network, one through each interface. Multipath routing is often utilized together with dead gateway detection. 2.4.3 Dead gateway detection The dead gateway detection (DGD) feature introduced in AIX V5.1 implements a mechanism for hosts to detect a dysfunctional gateway, adjust its routing table accordingly, and reroute Chapter 2. AIX continuous availability features 37
Page 1: Front cover IBM AIX Continuous Avai
Page 4 and 5: Note: Before using this information
Page 6 and 7: 2.3.7 Minidump . . . . . . . . . .
Page 8 and 9: vi IBM AIX Continuous Availability
Page 10 and 11: Trademarks The following terms are
Page 12 and 13: Engineering degree in Computer Scie
Page 14 and 15: Find out more about the residency p
Page 16 and 17: 1.1 Overview In May 2007, IBM intro
Page 18 and 19: 1.5 Continuous operations Continuou
Page 20 and 21: 1.6.2 Availability 1.6.3 Serviceabi
Page 22 and 23: IBM has tried to enhance FFDC featu
Page 24 and 25: 10 IBM AIX Continuous Availability
Page 26 and 27: 2.1 System availability AIX is buil
Page 28 and 29: On AIX 5.3, the only way to persist
Page 30 and 31: When used on a standalone server (s
Page 32 and 33: mirrored volume group on the client
Page 34 and 35: 2.2.1 Error checking Run-Time Error
Page 36 and 37: The PowerPC hardware gives software
Page 38 and 39: System dumps can also be user-initi
Page 40 and 41: Live dumps are small dumps that do
Page 42 and 43: Trace is a valuable tool for observ
Page 44 and 45: Component Trace uses mechanisms sim
Page 46 and 47: 2.3.14 syslog To display the boot l
Page 48 and 49: Logging can be added to many of the
Page 52 and 53: 2.4.4 EtherChannel network traffic
Page 54 and 55: 2.4.6 2-Port Adapter-based Ethernet
Page 56 and 57: operations) without affecting produ
Page 58 and 59: Quorum A quorum is a vote of the nu
Page 60 and 61: 2.5.8 Journaled File System-related
Page 62 and 63: Fast I/O failure is controlled by a
Page 64 and 65: display its output in a format suit
Page 66 and 67: For more detailed information about
Page 68 and 69: 54 IBM AIX Continuous Availability
Page 70 and 71: 3.1 AIX Reliability, Availability,
Page 72 and 73: This means that traditional AIX sys
Page 74 and 75: used by IBM service personnel, so t
Page 76 and 77: also be used to obtain a snapshot o
Page 78 and 79: 3.5 Live dump and component dump Li
Page 80 and 81: lfs filesystem ._0 | NO | ON/3 | OF
Page 82 and 83: .vmker | YES | ON/3 | OFF/3 .vmpool
Page 84 and 85: The output of Start a Live Dump is
Page 86 and 87: Table 3-3 Concurrent update termino
Page 88 and 89: We tested the installation of an ef
Page 90 and 91: Setting efix state to: STABLE +----
Page 92 and 93: mode, storage keys are called user
Page 94 and 95: Example 3-19 shows the SMIT menu fo
Page 96 and 97: might share a given hardware key. M
Page 98 and 99: KKEY_UPUBLIC, KKEY_FILE_DATA KKEY_U
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Note: Kernel keys and keysets, whic
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extension key-aware is determining
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added a protection gate for the int
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} printf("hardware keyset after KER
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} param=atoi(*(argv+1)); printf("Te
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Load the kernel extension so that a
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3 : 000000000000000A r4 : F10006C00
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3.7.7 User mode protection keys Use
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► The APIs provided by the system
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if (!strcmp(*(argv+1),"read")){ if
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strlen() at 0xd010da00 _doprnt(??,
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int pthread_attr_setukeyset_np (pth
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Machine State Save Area iar : 00000
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As a consequence, determining the r
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A Vue script or Vue program is a pr
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► An optional predicate The predi
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3. Interval probe manager The inter
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{ int count; count = count +1; prin
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► Errno names ► Signal names
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* will result in error out of read(
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This places a large part of the bur
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Note: The frequency of checks made
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Non-fragments 00000066 Promotions 0
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immediately after the returned stor
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This option should be used with car
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3.9.6 KDB commands for XMDBG ► xm
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138 IBM AIX Continuous Availability
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Name AIX version Hardware required
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Online resources These Web sites ar
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sysdumpdev 27 tprof 28 trace 28 trc
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subsequent reboot 71, 133 SUE 18 Sy
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