Module 5 Module Overview Lesson 1: Providing High Availability and Redundancy for Virtualization - PowerPoint Presentation

Module 5

Module Overview

Lesson 1: Providing High Availability and Redundancy for Virtualization

Why Is High Availability Important? Server downtime is unavoidable Servers are not always available Software or hardware maintenance or upgrade Application and operating system updates Component failure, power outages, natural disasters Critical services must be constantly available Running in virtual machinesWhen fails or unavailableIt must be serviced elsewhereGoal of high availabilityMake services availableEven when failure occurs Availability Downtime (per year) 99% 3.7 days 99.9% 8.8 hours 99.99% 53 minutes 99.999% 5.3 minutes

Redundancy in Windows Server 2012 R2 and Hyper-V Disaster recovery Hyper-V Replica for asynchronous replication CSV integration with storage arrays for synchronous replication Application / Service failover Non-cluster aware apps: Hyper-V app monitoring Virtual machine guest cluster: iSCSI , Fibre Channel, . vhdx sharing Virtual machine guest teaming of SR-IOV NICS I/O redundancy NLB and NIC Teaming Storage multi-path IO Multichannel SMB Physical server failure Live migration for planned downtime Failover clustering for unplanned downtime Hardware failure Windows hardware error architecture Reliability, availability, serviceability

Lesson 2: Implementing Virtual Machine Movement

Virtual Machine Moving Options Virtual machine and storage migration Includes from Windows Server 2012 to Windows Server 2012 R2 Quick migration – requires failover clustering Live migration requires only network connectivity Improved performance in Windows Server 2012 R2 Hyper-V Replica Asynchronously replicate virtual machinesConfigure replication frequency and extended replicationExporting and Importing of a virtual machineExporting while virtual machine is runningCan import virtual machine without prior export

How Storage Migration Works Hyper-V server Virtual machine Virtual hard disk st ack 1 2 3 4 5 Read/Write to source virtual hard disk Virtual hard disk is copied to destination Writes are mirrored to source and destination virtual hard disks After virtual hard disk is synchronized, virtual machine switches to copied virtual hard disk Source virtual hard disk is deleted Virtual machine is running uninterrupted during the migration process Virtual hard disk Virtual hard disk Compares with Storage vMotion

Overview of the Move Wizard Used for moving virtual machine or its storage While virtual machine is running Live migration or storage migration Alternatively, use Windows PowerShell cmdlets Move-VM or Move- VMStorageStorage migration is enabled by default (two at the same time)Live migration must be enabled before moving virtual machineAll virtual machine data can be moved to same locationOr you can specify location for each data itemOr you can move only virtual hard disk Virtual machine data items Virtual hard disks, current configuration, checkpoints, smart paging You can move only the virtual machine or also include data items

Live Migration of Non-clustered Virtual Machines Referred as a “shared nothing” live migration Virtual machine data can be local or on an SMB share Local: storage migration to move to target Hyper-V host SMB: leave data on the SMB 3.0 share In both cases virtual machine is moved Storage migration and virtual machine move Storage is migrated Virtual machine memory is moved Source storage is deleted Live migration speed is affected by Virtual machine memory size and modifications Bandwidth between source and destination Hyper-V hosts Compares with vMotion

Live Migration of Non-clustered Virtual Machines Virtual machine memory is moved in iterations Source is active and can be modifying memory Modified memory pages are sent after initial copy Repeats over newly modified pages Final copy iteration takes less than TCP timeout New MAC address is send to network switches Source Hyper-V host Destination Hyper-V host Configuration Virtual machine memory Configuration State State Virtual machine memory

Lesson 3: Implementing and Managing Hyper-V Replica

Prerequisites for Hyper-V Replica Windows Server 2012 with Hyper-V role Hyper-V Replica is part of the Hyper-V role At least two servers, usually in different sites Sufficient storage to host virtual machines Local and replicated virtual machines Connectivity between primary and replica sites Windows firewall configured to allow replicationHyper-V Replica HTTP and Hyper-V Replica HTTPSX.509v3 certificate for mutual authenticationIf certificate authentication is usedOtherwise, Hyper-V hosts must be in the same AD DS forest

Overview of Hyper-V Replica Hyper-V Replica has the following components: Replication engine Manages replication configuration and handles initial replication, delta replication, failover, and test-failover Change tracking module Keeps track of the write operations in the virtual machine Network module Provides a secure and efficient channel to transfer dataHyper-V Replica Broker server roleProvides seamless replication while a virtual machine is running on different failover cluster nodesManagement toolsHyper-V Manager, Windows PowerShell, Failover Cluster Manager

Overview of Hyper-V Replica Primary Site Secondary Site Initial Replica Replicated Changes CSV on Block Storage SMB Share File Based Storage

Enabling a Virtual Machine for Replication Replication is enabled per virtual machine Enable Replication Wizard Replica server Connection parameters Choose replication VHDs Chose replication frequency Configure additional recovery pointsChoose initial replication methodFailover TCP/IP SettingsPreconfigure IP address for replica virtual machineRequires integration servicesShould be configured on both the primary and replica server Primary 10.22.100.18 Virtual machine Replica 192.168.15.10

Hyper-V Replication Health Normal Less than 20% replication cycles are missed Last synchronization point was less than an hour ago Average latency is less than the configured limit Warning Greater than 20% of replication cycles have been missed More than hour since the last send replica Initial replication has not been completedFailover initiated, but not ‘reverse replication’Primary virtual machine replication is pausedCriticalReplica paused on the replica virtual machinePrimary server unable to send the replica data

Test Failover, Planned Failover, and Failover Test failover Non-disruptive testing, with zero downtime New virtual machine created in recovery site From the replica checkpoint Turned off and not connected Stop Test Failover Planned failoverInitiated at primary virtual machine which is turned offSends data that has not been replicatedFail over to replica serverStart the replica virtual machineReverse the replication after primary site is restored

Test Failover, Planned Failover, and Failover Failover Initiated at replica virtual machine Primary virtual machine has failed (turned off or unavailable) Data loss can occur Reverse the replication after primary site is recovered Other replication-related actions Pause Replication and Resume Replication View Replication HealthExtend ReplicationRemove Recovery PointsRemove Replication

Hyper-V Replica Resynchronization When normal replication process is interrupted Change tracking issues on primary server Replication issues with tracking logs Problems linking virtual hard disk with parent Time travel – virtual machine restored from backup Reverse replication after failover process Processor, storage, and network intensiveConfigured on primary virtual machineManual, automatic, or during scheduled timeIf more than 6 hours, perform full initial replication