Portions © 1998-2004 Intel Corporation | Portions © 1998-2004 Hewlett-Packard Corporation * Other brands and names may be claimed as the property of others.

Portions © 1998-2004 Intel Corporation | Portions © 1998-2004 Hewlett-Packard Corporation

* Other brands and names may be claimed as the property of others.

Intel, the Intel logo and Itanium is a trademark or registered trademark of Intel Corporation or its subsidiaries in the United States and other countries.

Portions © 1998-2006 Intel Corporation | Portions © 1998-2006 Hewlett-Packard Corporation

High Availability Architectures with HP Serviceguard

Guy Patrick, HP

HP Partner Technology Access Center

July 2006 Portions © 1998-2006 Intel Corporation | Portions © 1998-2006 Hewlett-Packard Corporation 2

Agenda

• High Availability Overview• High Availability Products and Solutions• Serviceguard Clustered File System• Cluster Management• Serviceguard and Workload Manager (WLM)• Serviceguard Application Integration

– Serviceguard Extension for SAP (SGeSAP)– Serviceguard and Oracle 10g

• Serviceguard for Linux (SG/LX)• Summary


Agenda





What are the total business consequences of an outage?

• Tarnished company reputation and customer loyalty• Lost opportunities and revenue• Idle or unproductive labor• Cost of restoration• Penalties• Litigation• Loss of stock valuation• Loss of critical data


Causes of Service Outages today

20%

40%

40%

Technology FailuresServers, Disks, Network

Human ErrorsOperational and Administrative ErrorsErrors under duress

Software FailuresOS, Middleware, Application


Achieving Availability

• Combination of 3 major pillars of availability– Technology

• Reliable architectural components (servers, disks, network, etc.)• Clustering software• Middleware• Data replication

– People and Processes• Training• Documentation• Change control

– Support Services• Rapid response time• Rapid diagnosis and repair• Availability of parts


High Availability versus Disaster Tolerance

• High Availability– Providing redundancy within a data center to maintain the service (with or

without a short outage)• Hardware failures• Software failures• Human error

• Disaster recovery– Usually providing a remote site with similar equipment that is shared

among multiple organizations (shared equipment model)– Personnel fly to the site with tapes and restore the service in days or

weeks• Disaster Tolerance

– Providing redundancy between data centers to restore the service quickly (tens of minutes) after certain disasters (dedicated equipment)

• Power loss• Fire, flood, earthquakes• Sabotage, terrorism


Agenda





Serviceguard for HP-UX

• Single Cluster up to 16 nodes– PA-RISC (9000) and Integrity servers

• For use when all nodes are in a single Data Center• Automatic failover

– up to 150 application packages (up to 900 services total); – supports up to 200 relocatable package IP addresses per cluster

• Cluster File System (CFS) support in SG versions >= 11.17 (heartbeat must be over Ethernet)• SCSI or Fibre Channel for disks• Single IP subnet for each heartbeat network (IPv4)

– Multiple heartbeat networks required (2 or more)• Ethernet• Infiniband• FDDI & Token Ring for legacy environments

• Local LAN failover and Auto-Port Aggregation• IPv6 support for data links only• File Systems and Volume Managers

– Journaled File System (JFS) and Online JFS• Although HFS is supported, it is not recommended for mission critical applications

– LVM– VxVM & CVM – volume manager-based mirroring is optional

• Quorum Device Required for 2-node clusters, optional for larger clusters

– Cluster lock disk for up to 4 nodes only– Quorum Server with up to 16 nodes


Serviceguard for Linux (SG/LX)

• Single Cluster up to 16 nodes– 2 to 4 nodes with Proliant servers using SCSI– Up to 16 nodes with Integrity servers or ProLiant servers using FibreChannel

• For use when all nodes are in a single Data Center• Automatic failover

– up to 150 application packages (up to 900 services total) – supports up to 200 relocatable package IP addresses per cluster

• SCSI or Fibre Channel for disks• Single IP subnet for each heartbeat network (IPv4)

– Multiple heartbeat networks required (at least 2)• Ethernet, supporting up to 7 Heartbeat subnets

• Network bonding for automatic network failover• File System and Volume Manager

– reiser, XFS, and ext3 file systems (Journaled file systems)– Logical Volume Manager (LVM and LVM2) that is included in the Linux distribution– RedHat Global File System (GFS)

• Dynamically loadable modules for Serviceguard installation• Quorum Device Required for 2-node clusters, optional for larger clusters

– Quorum Service with up to 16 nodes– Cluster Lock LUN for up to 4 nodes only


Multi-pathing Solutions

• Multi-pathing solutions for HP-UX– LVM/SLVM – PVLinks (active/standby)

– VxVM/CVM – DMP (dynamic multi-pathing, active/active)

– StorageWorks disk arrays (XP and EVA) – SecurePath (active/active)

– EMC disk arrays (Symmetrix and DMX) – PowerPath (active/active)

• Multi-pathing solutions for Linux– FibreChannel

• HBA FibreChannel driver• StorageWorks disk arrays – SecurePath• EMC disk arrays – PowerPath

– SCSI• Linux md driver


OS differences impacting SG functionality

• Extended / Campus Cluster is not supported on Linux– md implementation currently does not meet robustness requirements

• Data integrity protections are not as robust with Sistina LVM (Linux)– Manual activation of a volume used by an SG/LX package from another

server can corrupt data– HP-UX volume managers support exclusive activation mode to protect

against inadvertent activation from another server inside or outside of the cluster

• NFS fail over does not include file locks on Linux– Correcting requires Linux kernel changes– NFS v4 plans to support lock fail over and need distribution vendors to

support it

NOTE: Consider CFS or GFS instead of HA NFS.


SG cluster (local cluster – shared connectivity)

•All systems are physically connected to each disk•Maximum cluster size is 16 nodes•Each application runs on only one host at a time•Hosts can run multiple applications•Failover is possible to any node that is physically connected to the data

PowerRun Attn. Fault Remote

hp server rx5670

App A


hp server rx5670

App B


hp server rx5670

App C


hp server rx5670

App D

PUSH

READY

ALARM

MESSAGE

hp S t o r a g e W o r k s x p 1 2 0 0 0 d i s k a r r a y

hp S t o r a g e W o r k s x p 1 2 0 0 0 d i s k a r r a yhp S t o r a g e W o r k s x p 1 2 0 0 0 d i s k a r r a y

A

B

C

D

ClusterLock

2-nodecluster

Quorum ServiceHighly Available Quorum

Devicethat is not a member of the

clusterwhose quorum is being

satisfied

hpIntegrityrx4640

hpIntegrityrx4640


Failover Models

• Active / Standby– One or more nodes are reserved for failover use– Upon failover, the applications maintain performance due to spare capacity

• Active / Active– All nodes are running (different) applications– Upon failover, choice of

• Reduced capacity when multiple applications run on the same node• Shutdown less critical applications• Optional use of VSE technologies to guarantee resource entitlements

• Rotating Standby– Upon failover, the standby system becomes the new production system and the

repaired system becomes the new standby system• Active / Active (distributed application)

– All nodes are running an instance of the same application (e.g., RAC)– Depends on shared read/write access to the data– No failover of the application– Upon failure of a node (or instance), the users are sent to the remaining nodes


SG cluster – preventing split brain


hp server rx5670

App A


hp server rx5670

App B


hp server rx5670

App C


hp server rx5670

App D

PUSH

READY

ALARM

MESSAGE



A

B

C

D

•Each “sub-cluster” tries to form a cluster and run all of the applications•Two instances of the same application write to the same disks, resulting in data corruption

App A


SG cluster – preventing split brain (continued)


hp server rx5670

App A


hp server rx5670

App B


hp server rx5670

App C


hp server rx5670

App D

PUSH

READY

ALARM

MESSAGE



A

B

C

D

ClusterLock

2-nodecluster

Quorum ServiceHighly Available Quorum

Devicethat is not a member of the

clusterwhose quorum is being

satisfied

hpIntegrityrx4640

hpIntegrityrx4640

•Each “sub-cluster” tries to acquire the cluster lock on the cluster lock disk/lock LUN•The algorithm guarantees that only one sub-cluster will get it•One sub-cluster is forced to crash to prevent data corruption


Quorum Service (QS) (HP-UX and Linux)

• Alternative quorum arbitration method• Supports up to 50 clusters and maximum of 100 nodes• TCP/IP network connection required

• (Not required to be in the same subnet, although recommended to minimize network delays)

• Stand-alone HP-UX or Linux-based server(s) outside of the Serviceguard cluster whose quorum is being satisfied• Runs as a real-time process• The Quorum Service (QS A.02.00)

•can be configured in a package in a cluster•cannot reside in the same cluster that uses it•do not configure two clusters that use the same Quorum Service package

•Bonding (Linux) or APA (HP-UX) can be used to increase network availability to the Quorum Service


Agenda





What is the SG Cluster File System?

• True multi-reader / multi-writer CFS– Applications on different nodes within the cluster can access the

same files simultaneously– Similar to distributed raw volumes in SG today, except with file

systems– Applications are responsible to ensure that simultaneous access

does not result in application (logical) data corruption• Does provide locking functions with POSIX file system locking

semantics (lockf, similar to multiple users accessing the same file on a single system)– POSIX file system semantics are advisory only

– Locks can refer to regions of a file


Storage Options in a Serviceguard Cluster

A cluster file system is concurrently accessed by all cluster nodes.

A failover file system is exclusively activated by one node and

can transition between nodes.

/project

/proj2

/proj1

Local Root Local Root

/mnt1VxFS

/mnt2VxFS

CFS Storage

VxFS

Raw Volume

Cluster Node A Cluster Node B

A raw volume can be exclusively activated and failed over OR concurrently accessed


VEA manages CFS mount points and VxVM and CVM volumes

In HP-UX 11iv3 (11.31), we expect that fsweb will launch VEA

Management GUI VERITAS Enterprise Administrator (VEA)


Adoption of Serviceguard CFS

• Overall message:– No forced transition

– Transition can occur in customer’s timeframe

– LVM/SLVM will continue to be supported and enhanced

– We don’t expect all customers or ISVs to have a need for the CFS functionality

• Benefits of a CFS vary with the application and must be evaluated on a case-by-case basis

• There are targeted applications where we expect to see SG/CFS adoption

• ISVs will not need to re-certify with the new version of Serviceguard• ISVs may want to take advantage of the CFS, and that may require

development effort for:– Installation / configuration processes and scripts

– Application-level locking when sharing data and files


HP SG/LX & Red Hat GFSOverview

HP and Red Hat announce support for highly available, manageable, and scaleable Linux clusters that combine leading technologies:

– HP Serviceguard for Linux for high availability

– Red Hat Global File System (GFS) for a single cluster-wide file system

Product details

HP Serviceguard Linux & Red Hat GFS SW (T2798AA)

#001 - 1 year SGLX + GFS SW update subscription LTU

#003 – 3 years SGLX + GFS SW update subscription LTU

www.hp.com/go/sglx/gfs

+


Serviceguard Long-term Strategy

• Serviceguard– SG is HP’s strategic clustering product for HP-UX and Linux

• VCS: Veritas Cluster Server– VCS is NOT part of any bundle being offered by HP

• Volume Managers– LVM will continue to be the default volume manager

– LVM and SLVM will continue to be supported and enhanced

– CVM will be required when using the CFS

– Multiple volume managers can be used in the same cluster


Compatibility with HP-UX Versions

• Serviceguard CFS will be supported with:– HP-UX 11i v2 September 2004 release and greater– Serviceguard 11.17 (Q3/2005)– VERITAS Storage Foundation 4.1 delivered by HP– Both HP 9000 and HP Integrity Server

• At this time, SG/CFS will NOT be supported with:– HP-UX 11i v1– Earlier versions of HP-UX 11i v2– HP-UX 11.0 or earlier


Agenda





• View and manage up to 50 HP-UX and Linux Serviceguard clusters and up to 100 nodes

• Graphical user interface (Java based)

• Multiple subnet support• Status badges and tool tips• Property sheets• Auto refresh (Polling)• Large scale cluster display

• Cluster, node and package administration

• Run and halt clusters, nodes and packages

• Change package and node switching parameters

• Package drag and drop• Alerts panel and event browser• Extensive online help

Serviceguard Manager Features Overview


• Configuration• Cluster create/modify/delete• Package

create/modify/delete• Operation Log (Progress

messages) for configuration and administration operations

• Role based access• Management of cluster and

package access policies• Administration for non-root

user• Integrated with Openview

Operations 8.0• Integrated with HP SIM 4.1• Serviceguard Manager can run

as client on HPUX, Linux and Windows platform

• Free!

Serviceguard Manager Features Overview (continued)


Agenda





Serviceguard and Workload Manager

• Workload Manager (WLM) – WLM allows the specification of SLOs for SG packages that may not be

active on the system. Each SLO is conditional on which server the package active

– When a failover or package movement occurs, WLM detects it and enforces the SLO – the package gets the priority and the resources specified

– WLM automatically activates/deactivates TiCAP processors to reduce the performance impact of an application failover in active-active single or multi-site disaster tolerant configurations

– Using WLM on a Pay per use (PPU) basis reduces the cost of active-standby single or multi-site disaster tolerant configurations


Resource management of your adaptive infrastructure

nPar 1 nPar 2vPar 1.1

resource partition 1.1.1


resource partition 1.1.n

vPar 1.2




vPar 2.1




vPar 2.2




12

2

3

When app in RP 2.1.2 failsSG starts it in RP 1.1.21 - WLM reallocates resources across RPs inside the vpar

If that is not enough

2 – WLM pulls CPUs fromvPar 1.2 and/or from nPar 2

If that isn’t enough

3 – WLM activates Temporary CapacityProcessors to meet the demand


Integration of Workload Manager and Serviceguard

• WLM SLO Condition Statement– Allows for the turning on/off of SLOs based on time, day, date or

some event on the system

• WLM Serviceguard Toolkit– Shipped with the WLM product – Notifies WLM when a named Serviceguard package is activated

on the system– sgpkgactive command outputs activation status of the named

package at each WLM interval– This info is passed to WLM using the wlmrcvdc scripting toolkit,

which is also shipped with the product


Agenda





HP Serviceguard Developer’s Toolbox

• Framework to facilitate quick and painless integration of your application with HP Serviceguard (Linux and HP-UX)

• Toolbox (delivered as a .zip file) includes– A standardized integration template written in Posix Shell.

Template may be customized for applications managed by HP Serviceguard in either HP-UX or Linux environments

– Validation guidelines and test tool– Documentation on

• Template design • Customization tips• Best practices guidelines for integration

– Exampleswww.hp.com/go/dsppha


Serviceguard (HP-UX) Toolkits

• Enterprise Cluster Master Toolkit (ECMT)– Fully-tested and supported collection of integration templates for

certain popular third-party applications– Supported Oracle 10g – as of December 2004

• HA NFS Toolkit– Pre-tested and supported templates to make NFS servers highly

available

www.hp.com/go/softwaredepot/ha


Serviceguard (Linux) Toolkits

• Fully tested and supported integration templates– Oracle9i DBMS– Oracle10g DBMS– NFS

• Contributed Toolkits (pre-tested templates for popular 3rd party applications)– File System

• Samba– Database

• PostgreSQL• MySQL

– Other• Sendmail• Apache• Tomcat

www.hp.com/go/softwaredepot/ha


Agenda





Serviceguard extensions for SAP (SGeSAP) and (SGeSAP/LX)

• Integrate SAP R3 with:• Serviceguard

– Toolkit template for easily configuring SAP with Serviceguard (HP-UX and Linux)

– Options to on how to configure the Central Instance (CI) and the Database (DB) servers

• Metrocluster (HP-UX only)– Optional template to create a disaster tolerant architecture for SAP(Configuration example shown in the Metrocluster section of this

presentation)

+www.hp.com/go/sap/sgesap


Agenda





Oracle 10g Support (single instance)

HPUX

HP File Systems/Volume Mgr

10g with HP ClusterMembership and Storage Mgmt

SG Clustering Components

• HP supports Oracle 10g (single instance) configurations that use:

• Serviceguard cluster membership for High Availability configurations

• HP-UX supported volume managers to store Oracle data

• LVM, VxVM and CVM/CFS

• The SG package manager to provide HA for applications running on the same cluster as Oracle 10g single instance

Ora

cle

10g

and

SG

Man

aged

App

licat

ions

SGPackageManager

SG

Inte

grat

ion

code


Oracle 10g RAC

• Oracle Real Application Clusters (RAC) 10g is an option to Oracle 10g Enterprise Edition

• Differences from the previous Oracle9i RAC product include:– Clusterware is built-in (formerly known as Cluster Ready Services or

CRS)– Automatic Storage Management (ASM) software can be used to

manage storage for the RAC database– Performance improvements– “Zero downtime” (rolling upgrade) for certain Oracle patches

• NOTE: Oracle allows customers the choice of using the built-in Oracle cluster membership capability or utilizing platform-specific clusterware such as SGeRAC


SGeRAC with Oracle10g RAC

• Increases availability for non-RAC processes and applications running on nodes within the RAC cluster

– Oracle Clusterware focuses only on Oracle-specific processes and resources– 10g R2 Clusterware is expected to provide a package manager and API

for protecting non-Oracle processes• Is required when using a volume manager

– Greater flexibility when working with LUNs• Features such as OS mirroring, striping, etc.

– SLVM or CVM provides concurrent access to the same storage by multiple nodes

• Provides reliable node membership information through – Tight kernel integration – Real-Time priority execution

• Improves network reliability through monitoring and failover management of

– User LAN failover– Cluster interconnect failover– IPv6 networks


Agenda





Designed, developed, delivered and supported

by

bringing enterprise–

strength high availability to the Linux platform –

x86 and Integrity servers

Offers a completely integrated high

availability clustering solution available on a range of storage and servers that provides efficient, continuous

access to mission critical applications,

information, and services

HP Serviceguard for Linux

+


Flexible and scalable entry-level fibre channel cluster

powered ProLiant and Integrity

servers and Virtual Arrays

(MSA1000, MSA1500cs

VA7xx0, EMC CLARiiON)Scalability/Performance

Availa

bili

ty

Simple and affordable, powered by ProLiant servers and Modular Smart

Array 500 G2 (ProLiant only)

Plugged into the data center fabric to

maximize scalability and availability with extended distance

clustering option for disaster tolerance

(EVA 3000, EVA 5000, XP48, XP128, XP512, XP1024,

EMC Symmetrix)

Departmental

clusters

Enterprise clusters

Infrastructure clusters

HP Serviceguard for Linux Configurations

Enterprise Linux

distributions:


Winner best clustering solution!

LinuxWorld Feb 2005

• HP’s Virtual Server Environment for Linux was named Best Clustering Solution in the LinuxWorld Products Excellence Awards program

• The awards recognize important innovations in Linux and open source technologies

• HP released and demonstrated the first version of VSE for Linux on HP Integrity Superdome• HP gWLM provides the policy engine to allocate virtual server

resources in a Linux operating system• HP Serviceguard for Linux provides the high availability

clustering component of the solution


HP Serviceguard for Linux and cluster extension

• Disaster recovery to protect against the risk of downtime, whether planned or unplanned

• Automatic failover/failback to reduce the complexity involved in a disaster recovery situation

• Ensures the highest standards in data integrity by leveraging the inherent advantages of HP StorageWorks XP or EVA disk array remote mirroring

World’s first DR solution on Linux!

IP network(s)

Data center B

Metropolitan-wide distances or farther

Data center A

IP network(s)

MAN/WAN

MAN/WAN

Storage network(s)

Mirror

Data


Agenda





HP’s advantage

HP uses its vast experience with complex systems to provide the most effective availability solutions in

the industry

• Global HA supplier• Multi-OS solutions• End-to-end service and support

portfolio• Strategic partnerships


For more information on HP’sHigh Availability offerings …

Reference Links:

• http://www.hp.com/go/ha

• http://docs.hp.com/hpux/ha

• HP Serviceguard Developer's Toolboxhttp://www.hp.com/go/dsppha


DSPP Tools & Resources for Itanium®2 Architecture Set You Up for Success

Software– development environments,

compilers, operating systems, installation/configuration tools, performance tools and more

Technical documentation– white papers, tutorials,

references documents and manuals, FAQ’s, known problems, sample code, etc.

Training and Education– online and classroom training

Community– Itanium® architecture forums,

source code repository, document sharing and mailing lists

Equipment– rentals and purchase

discounts Partner Resources

News & Events


Where to go …

Software Developer Resource Kit for the Intel® Itanium®2 microarchitecture: www.hp.com/go/hpitaniumdvd

Development and Business Resources from HP & Intel for HP Integrity-based solutions: www.hp.com/go/dspp-eap

Contact points for additional information, general support, equipment, localization resources and more:

Americas email: [email protected]

telephone 1.800.249.3294

Europe email: [email protected]

telephone 800.100.929.70

Asia-Pac email: [email protected] or go to www.hp.com/go/dspp for local country contacts


Complete Survey to Win

HP & Intel are giving away an HP laptop

to 1(one) lucky winner!!• Promotion Period ends August 20, 2006• Attend a webcast AND complete

the post-event survey. • Full promotion details can be found on DSPP at:

http://h21007.www2.hp.com/dspp/bus/bus_BusDetailPage_IDX/1,1252,9434,00.html


• Tuesday, August 22 – MPI Libraries

• Tuesday, September 19 – Caliper Update

• Tuesday, October 24 – Open MP

Sign up for the DSPP newsletter to get the latest webcast information sent to you

directly.

Webcast replays may also be found at: www.hp.com/go/itaniumwebcasts

VTune webcast replay is now available at:http://h21007.www2.hp.com/dspp/ne/ne_EventDetail_IDX/1,1394,1245,00.html

More Events


Intel® Early Access Program - Technology

• The Early Access Program (EAP) gives you access to Intel® technology to support your current development cycle as well as early access to tools and information on new technologies. Your membership includes:– Early access to pre-release software development platforms– Access to Intel and 3rd party software and testing tools– Training through Intel® Software College and Web events– Technical content and how–to articles– Protected remote access to

easily evaluate and develop software safely and securely on platforms over the Internet


Intel® Early Access Program -Marketing Opportunities and Support

• Extensive marketing and business development opportunities: – Inclusion in online and print versions of the Intel® Developer

Solutions Catalog– Intel quotes to support your PR– Case studies– Access to Intel’s event marketing asset kit– Participation in selected industry events and trade shows

• Support in your development efforts provided through:

– Access to an Intel Account Representative who will act as your primary contact

– Intel® Premier Support for confidential technical support

– 24/7 online support via www.intel.com/software/support


Related Intel® Resources

• Intel® Early Access Program – http://www.intel.com/software/EAP

• Intel® Software Network– http://www.intel.com/software

• Intel® Software College– http://www.intel.com/software/college

• Intel® Software Development Tools– http://www.intel.com/software/products

• Experience Intel® Itanium® 2 Architecture– http://www.intel.com/cd/ids/developer/asmo-na/eng/661

76.htm


Q&A Session:To ask a question over the phone, press *1 on your touch-tone telephone.



Serviceguard feature differences by OS (1 of 2)

Feature HP-UX LinuxCluster lock Disk LUN

RS-232 heartbeat Yes No

Exclusive activation (volume manager) Yes No

IPv6 support Yes No

Status via SNMP Yes No

NFS lock failover Yes No


Serviceguard feature differences by OS (2 of 2)

Feature HP-UX LinuxMulti-path SecurePath/AutoPath Qlogic

SecurePath (check dist & errata)

Mirrored boot disk MirrorDisk/UX Smart array HW RAID

md SW RAID (check docs)

Maximum LUN support 11.0 – 4,000

11.11 – 8,000

11.23 – 16,000

RH 2.1 – 119

RH 3 – 256

SUSE/UL - 128

NIC support Ethernet, TR, FDDI, ATM, X.25

Ethernet only

Redundant networking Local LAN switch/APA Linux bonding


Serviceguard offerings differences by OS

Offering HP-UX Linux

DB2, Informix, Sybase, (ECMT) toolkits Yes No

PostgresSQL, Sendmail toolkits No Yes

Continentalclusters Yes No

Metrocluster (EVA, CA/XP, EMC SRDF) Yes No

Extended / Campus Cluster Yes No

Cluster Extension XP No Yes

Serviceguard Extension for RAC (SGeRAC) Yes No

Virtual Server Environment (VSE)(gWLM available for Integrity Linux)

Yes Partial

VERITAS VxVM/CVM support Yes No

Cluster File System Yes – VERITAS CFS

Supported by HP

Red Hat GFS

Integrity SCSI support Yes No

Serviceguard Extension for Faster Failover (SGeFF) Yes No


Products

Bundle

SG 11.17

+ ECMT

VSF 4.1 Enterprise Tools

DB Tools CVM/CFS SGeRAC

T2771BA – SGSM X X

T2772BA – SGSMP X X X

T2773BA – SGSMO X X X

T2774BA – SGSMOP X X X X

T2775BA – SGCFS X X X X

T2776BA – SGCFSO X X X X X

T2777BA – SGCFSRAC X X X X X X

Serviceguard CFS Bundles Overview(HP-UX)

Option to all bundles: VERITAS Volume Replicator (VVR)


Serviceguard Configuration

• The Application Package defines:

1. How to startup the application

2. How to shutdown the application

3. How to monitor the application

4. What resources are used by the application• Nodes package can run on• Networks required by package• Disk Volume Groups required by package• Services to monitor• User-defined resources to monitor


Protecting against split brain and data corruption

• ServiceGuard uses a “tie-breaker” or Quorum Device to prevent “Split-Brain” of the cluster– Cluster lock disk (HP-UX) or Cluster LUN (SG/LX)

• single cluster lock disk (when all servers are in a single data center)• dual cluster lock disks (when the servers are distributed across two data centers)

– Quorum Server • a (small) server that is outside of the cluster

• Without a tie breaker, split-brain can occur when:

– a network failure splits the cluster into 2 equal halves-OR-

– exactly half of the servers in the cluster fail all at once

• Unless split-brain is prevented, data corruption will occur if the application runs concurrently on both “halves” of the cluster and modifies the same single copy of the data


Cluster Lock Disk (HP-UX Only)Cluster Lock LUN (Linux Only)

• A special area on an LVM disk located in a volume group that is shareable by all nodes in the cluster

• When a node obtains the cluster lock, this area is marked so that other nodes will recognize the lock as “taken.”

• A cluster lock disk for HP-UX can be employed as part of a normal volume group containing user data

• Lock requirements– Usable for clusters between 2 and 4 nodes– Greater than four nodes – lock disk is not allowed; however a quorum service may

be used

Cluster Lock LUN• Alternative to QS• Similar to SG lock disk (on HP-UX)• Requires exclusive use of a single LUN (Linux partition of size 100K)

Cluster Lock Disk

Portions © 1998-2004 Intel Corporation | Portions © 1998-2004 Hewlett-Packard Corporation * Other brands and names may be claimed as the property of others.

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