Red Hat CLUSTER FOR ENTERPRISE LINUX 5.0 Guida di Installazione

Red Hat Enterprise Linux 5Cluster Suite OverviewRed Hat Cluster Suite for Red Hat Enterprise Linux 5Edition 5

Chapter 1. Red Hat Cluster Suite OverviewClustered systems provide reliability, scalability, and availability to critical production services.Using Re

you can match the number of nodes according to load requirements. If a node in a load-balancingcluster becomes inoperative, the load-balancing softwar

Global Network Block Device (GNBD) — An ancillary component of GFS/GFS2 that exportsblock-level storage to Ethernet. This is an economical way to make

The Red Hat Cluster Suite cluster infrastructure provides the basic functions for a group of computers(called nodes or members) to work together as a

Fig u re 1.2. C MAN/DLM O verview1.3.2. Lock ManagementLock management is a common cluster-infrastructure service that provides a mechanism for otherc

Power fencing — A fencing method that uses a power controller to power off an inoperable node.Two types of power fencing are available: external and i

Fig u re 1.4 . Fib re Ch an nel Swit ch Fen cin g ExampleSpecifying a fencing method consists of editing a cluster configuration file to assign a fen

Fig u re 1.5. Fen cin g a No d e wit h D u al Po wer Su p p lies⁠Chapt er 1 . Red Hat Clust er Suit e Overview13

Fig u re 1.6 . Fen cin g a N o d e wit h Du al Fib re Ch an nel Co n n ect io nsYou can configure a node with one fencing method or multiple fencing

Fig u re 1.7. C CS O verviewOther cluster components (for example, CMAN) access configuration information from theconfiguration file through CCS (refe

Fig u re 1.8. Accessin g Co n f ig u rat io n In f o rmat io nThe cluster configuration file (/etc/cluster/cluster.conf) is an XML file that describe

service. A high-availability cluster service can fail over from one cluster node to another with noapparent interruption to cluster clients. Cluster-s

Fig u re 1.9 . Failo ver Do main sFigure 1.10, “ Web Server Cluster Service Example” shows an example of a high-availability clusterservice that is a

Fig u re 1.10. Web Server C lu st er Service ExampleClients access the cluster service through the IP address 10.10.10.201, enabling interaction with

GFS/GFS2 is a native file system that interfaces directly with the Linux kernel file system interface(VFS layer). When implemented as a cluster file s

The Cluster Logical Volume Manager (CLVM) provides a cluster-wide version of LVM2. CLVMprovides the same capabilities as LVM2 on a single node, but ma

Fig u re 1.11. CLVM O verviewYou can configure CLVM using the same commands as LVM2, using the LVM graphical user interface(refer to Figure 1.12, “ LV

Fig u re 1.12. LVM G rap hical User In t erf ace⁠Chapt er 1 . Red Hat Clust er Suit e Overview23

Fig u re 1.13. Co n g a LVM G rap hical User In t erf aceRed Hat Ent erprise Linux 5 Clust er Suit e Overview24

Fig u re 1.14 . Creat in g Lo g ical Volu mes1.7. Global Net work Block DeviceGlobal Network Block Device (GNBD) provides block-device access to Red H

Red Hat Enterprise Linux 5 Cluster Suite OverviewRed Hat Cluster Suite for Red Hat Enterprise Linux 5Edition 5

Fig u re 1.15. G NBD O verview1.8. Linux Virt ual ServerLinux Virtual Server (LVS) is a set of integrated software components for balancing the IP lo

Fig u re 1.16 . Co mpo nen t s o f a R u n nin g LVS Clu st erThe pulse daemon runs on both the active and passive LVS routers. On the backup LVS rout

Synchronize the data across the real servers.Add a third layer to the topology for shared data access.The first option is preferred for servers that d

Fig u re 1.17. T wo- T ier LVS T o p olo gyService requests arriving at an LVS router are addressed to a virtual IP address or VIP. This is apublicly-

Also, the active LVS router dynamically monitors the overall health of the specific services on the realservers through simple send/expect scripts. To

Fig u re 1.18. T hree- Tier LVS T op o lo g yThis topology is suited well for busy FTP servers, where accessible data is stored on a central, highlyav

Figure 1.19, “ LVS Implemented with NAT Routing” , illustrates LVS using NAT routing to move requestsbetween the Internet and a private network.Fig u

1.8 .3.2 . Direct Ro ut ingDirect routing provides increased performance benefits compared to NAT routing. Direct routingallows the real servers to p

correct IP/MAC address combination receives the packet. The IP/MAC associations are stored in anARP cache, which is cleared periodically (usually ever

Because of its efficiency and ease-of-use, administrators of LVS should use firewall marks instead ofpersistence whenever possible for grouping connec

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You can populate the database of one lu ci instance from another lu ciinstance. That capabilityprovides a means of replicating a lu ci server instance

Fig u re 1.22. lu ci clu st er T ab⁠Chapt er 1 . Red Hat Clust er Suit e Overview37

Fig u re 1.23. lu ci st o rag e T ab1.9.2. Clust er Administ rat ion GUIThis section provides an overview of the system-config-cluster cluster adminis

Fig u re 1.24 . Clu st er C o n fig urat io n T oo lThe Clu st er C o n fig urat io n T oo l represents cluster configuration components in theconfi

Fence Devices — Displays fence devices. Fence devices are represented as subordinateelements under Fence Devices. Using configuration buttons at the b

Fig u re 1.25. Clu st er St at u s T o o lThe nodes and services displayed in the Clu st er St at u s T oo l are determined by the clusterconfiguratio

T ab le 1.1. Co mman d Lin e T oo lsCo mman d Lin eT o o lUsed Wit h Pu rp o seccs_tool —ClusterConfigurationSystem ToolClusterInfrastructureccs_too

Fig u re 1.26 . T he Welco me Pan elThe following sections provide a brief description of the Piran h a Co nf ig u rat io n To o lconfiguration pages

Fig u re 1.27. T he CONTROL/MONITORING Pan elAuto updateEnables the status display to be updated automatically at a user-configurable interval setin t

The GLOBAL SETTINGS panel is where the LVS administrator defines the networking details for theprimary LVS router's public and private network in

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NAT Router IPThe private floating IP in this text field. This floating IP should be used as the gateway forthe real servers.NAT Router netmaskIf the N

Redundant server public IPThe public real IP address for the backup LVS router.Redundant server private IPThe backup router's private real IP add

Fig u re 1.30. T he VIRTUAL SERVERS Pan elEach server displayed in the VIRTUAL SERVERS panel can be configured on subsequent screens orsubsections.To

Fig u re 1.31. T he VIRTUAL SERVERS Su bsect io nNameA descriptive name to identify the virtual server. This name is not the hostname for themachine,

Firewall MarkFor entering a firewall mark integer value when bundling multi-port protocols or creating amulti-port virtual server for separate, but re

Fig u re 1.32. T he REAL SERVER Su b sect io nClick the ADD button to add a new server. To delete an existing server, select the radio button besideit

Fig u re 1.33. T he REAL SERVER Co nf ig u rat io n Pan elThis panel consists of three entry fields:NameA descriptive name for the real server.NoteTh

The value can be arbitrary, but treat it as a ratio in relation to other real servers.1.1 0.4 .3. EDIT MONITORING SCRIPTS Subse ct io nClick on the MO

NoteIf an external program is entered in the Sending Program field, then the Send fieldis ignored.SendA string for the nanny daemon to send to each re

Chapter 2. Red Hat Cluster Suite Component SummaryThis chapter provides a summary of Red Hat Cluster Suite components and consists of the followingsec

IntroductionThis document provides a high-level overview of Red Hat Cluster Suite for Red Hat Enterprise Linux 5and is is organized as follows:Chapter

cluster.confThis is the cluster configuration file. Thefull path is /etc/cluster/cluster.conf.Cluster Manager(CMAN)cman.koThe kernel module for CMAN.

fence_vixelFence agent for Vixel Fibre Channelswitch. fence_sanbox2Fence agent for SANBox2 FibreChannel switch. fence_iloFence agent for HP ILO inter

gnbd_importCommand to import and manageGNBDs on a GNBD client. gnbd_servA server daemon that allows a node toexport local storage over the network.LV

lvs.cfThis is the LVS configuration file. Thefull path for the file is /etc/sysconfig/ha/lvs.cf.Directly or indirectly, all daemons gettheir configur

fence_drac (8) - fencing agent for Dell Remote Access Cardfence_egenera (8) - I/O Fencing agent for the Egenera BladeFramefence_gnbd (8) - I/O Fencing

lvm (8) - LVM2 toolslvm.conf [lvm] (5) - Configuration file for LVM2lvmchange (8) - change attributes of the logical volume managerpvcreate (8) - init

Revision HistoryRevisio n 5.11- 6 Mo n Sep 8 2014 St even Levin eVersion for 5.11 GA releaseRevisio n 5.11- 4 Mo n Ju n 30 2014 St even Levin eBe

co mman d lin e t o ols t ab le, Co mman d Lin e Ad min ist rat io n To olsco mp at ib le h ard ware- cluster components, Compatible HardwareCo ng

- VIRTUAL SERVER subsection, VIRTUAL SERVERS- Firewall Mark , The VIRTUAL SERVER Subsection- Persistence , The VIRTUAL SERVER Subsection- Scheduling ,

1.1. T ypographic ConventionsFour typographic conventions are used to call attention to specific words and phrases. Theseconventions, and the circumst

Whether mono-spaced bold or proportional bold, the addition of italics indicates replaceable orvariable text. Italics denotes text you do not input li

1.3. Not es and WarningsFinally, we use three visual styles to draw attention to information that might otherwise be overlooked.NoteNotes are tips, sh