Virtual DR: Disaster Recovery Planning for VMware ... · Virtual DR: Disaster Recovery Planning for...
Transcript of Virtual DR: Disaster Recovery Planning for VMware ... · Virtual DR: Disaster Recovery Planning for...
© 2008 Silverton Consulting, Inc. 1
Virtual DR: Disaster RecoveryPlanning for VMware Virtualized
Environments VMware DR considerations
Raymond LucchesiPresidentSilverton Consulting, [email protected]://www.SilvertonConsulting.com
© 2008 Silverton Consulting, Inc. 2
VMware server virtualization is being touted as a nearpanacea for DR by making it easier than ever to recoverservers to a secondary site. But, just as virtual serverscomplicate backup procedures, server virtualization has animpact on storage infrastructures and may requiretweaking disaster recovery plans for storage systems. Inthis session, I will address these issues, replication andrestore capabilities with virtualized servers and other topicsincluding the following:
* With virtualization you may end up with more servers torecover -- what is the possibility of orphaned or unusedservers?* What are VMware Site Recovery Manager and VMotion --and are they needed for an effective DR plan?* Are there any gotchas related to VMware Site RecoveryManager -- does it need a certain type of storage?
Abstract
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VMware DR Advantages
• Testability
• Hardware independence
• P2V, V2V and V2P
• Data encapsulation
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DR Testability
VM DR testable at local or remote site:
• Easy image copy availability
• Easy configuration changes to run VM onother ESX servers
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Hardware (HW) Independence
• Primary <> DR site HW
• VMkernal isolates and virtualizes all CPU,networking and storage HW interaction
• Except Raw Device Mapping (RDM)
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P2V, V2V and V2P
• P2V -- Physical server hosted as a VM at DR sitevia VM converter and third-party tools
• V2V -- DR site ESX server HW different thanprimary site HW
• V2P -- VM hosted as a physical server at DR site,requires compatible HW, third-party tools
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Data Encapsulation
• VMware encapsulates all VM data in few filesunder one directory
• Except RDM data
• Directory file data can be restored to re-start aVM on a remote site
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VMware Datastores
• VMware clustered file system (VMFS)
• DAS
• iSCSI
• FC storage
• NAS/NFS volumes
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VMFS DatastoreVMware cluster file system
• Distributed, sharable file system, shared across ESXservers and VMs
• Flexible block sizing
• Flexible file system/volume sizing
• File system snapshoting
LUN0LUN0
LUN0LUN0
LUN0LUN0
LUN7
LUN0LUN0
LUN0LUN0
LUN0LUN0LUN13
LUN0LUN0
LUN0LUN0
LUN0LUN0
LUN0
VMFS0 VMFS1 VMFS2
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Files For Each VM(.vmx, .vmdk and others)
• File(s) that encapsulate the config, O/S,application and data for a Virtual Machine (VM)
LUN0LUN0
LUN0LUN0
LUN0LUN0
LUN0
VMFS0
vm1.vmx
vm1.vmdk
vm2.vmx
vm2.vmdk
vm3.vmx
vm3.vmdkESX
VM 1
VM 2
VM 3
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Raw Device Mapping (RDM)
• Virtual compatibility mode
• VMFS mapping file
• Virtualizes physical device I/O
• VM snapshots supported
• Physical compatibility mode (FC or iSCSI)
• VMFS mapping file
• I/O direct to physical device bypassing ESX I/O
• FC link/HBA port or NIC dedicated to VM
• Direct mode via iSCSI initiator
• Shared NIC
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Recap VMware
• Provides easy DR testability
• Removes H/W dependencies
• Encapsulates all VM data
• RDM data lone exception
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VMware Backup Alternatives
• Backup SW agents on VMs• File level backup and restores
• Backup SW agents on ESX service console• Image level backup and restores
• VMware consolidated backup (VCB)
• CDP
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VM Backup Agents
• Backup agents on VM read files
• VM backup agent transfers file data tobackup server over LAN
• Backup server writes data to backup target
→ No .vmdk or .vmx images for DR
→ Ability to do file level restores
→ Performance considerations
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ESX Service Console Backup Agents
• Backup agents on ESX service console reads.vmdk and .vmx files
• ESX backup agent transfers file data to backupserver over LAN
• Backup server writes data to backup target
→ No file level restore
→ Performance considerations
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VM Consolidated Backup (VCB)
• “LAN-free” backup of VMs
• Suspend VM
• Uses VM snapshot to replicate datastores
• Catalog’s VM state on snapshot
• Resume VM
• Snapshots mounted or streamed to VCB proxy
• Snapshots backed up to target media via otherbackup SW
• VCB releases snapshots after backup
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VM Consolidated Backup (VCB)(Continued)
• Requires
• VCB backup proxy (Windows 2003) server
• Other Backup SW
• Shared SAN access to VMFS and NAS datastoresand snapshots
• VI3 supports all datastore types for VCB
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VMware Snapshot
• Copy of disk, memory, CPU state takenpoint-in-time
• Parent-child relationship
• .REDO bitmap files
• Activity state of VM?
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VCB
Works well for…
• Offloading ESX server backup cycles
• Image copies of VMs
• File level restores for Windows
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Works poorly for…
• VMs with large .vmdk -- need file levelbackups
• OLTP or always on VMs
• RDM physical mode
VCB
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VCB Integrated SW tools
• VizionCore VrangerPRO
• EsXpress
• Vmts.net -- vmbk.pl
• Symantec Backup Exec system recovery option
• Also supported by Symantec Backup Exec, NetBackup, EMC Networker, CommVault Galaxy andothers
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VMware CDP
• VM based write splitters protect VM files
• Network and storage array writesplitters protect disk images
• Some CDPs support ESX write splittersvia Veritas Volume manager
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VMware Backup Recap
• How you backup VMs impacts DR
• VCB can help DR
• For the right VMs
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VMware Local Clustering
• DRS for performance optimization
• HA for fault tolerance
• Both depend on:
• VMotion to migrate active VMs
• Shared access to datastores
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VMotion• Running VM quiesced, snapped and terminated
• Activates new VM on another ESX sever
• Requires• Shared access to datastores• Compatible H/W
• VM data stays in place
ESX0
VM 0
VM 1VM 2
VM 3
ESX1
VM 4
VM 5
VM 6
VM 0
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VM Dynamic Resource Scheduler (DRS)
• User defined pools of resources and VMprioritization
• Automatic or manually balances VM load acrossdefined resource pools
• Also used for service outages
• Also supports power management
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VM High Availability (HA)
• Local fault tolerant cluster of ESX serversusing heartbeat to detect failed VM/ESXserver
• Reserves resources for fail over
• In combination with DRS selects optimalplacement for restart
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Why DRS, HA And VMotion For DR
• Can operate both at local and remote siteto optimize performance
• Resource pools and VM prioritization alsoneeded for DR
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VMware DR Alternatives
• Non-RDM DR
• VMware Site Recovery Manager
• RDM DR
• Non-VMware replication-clustering
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Non-RDM VM DR
Some of the steps required to restart VM at remote site:
• Backup/image copies available
• H/W and S/W to run ESX server
• Configure ESX server to run VM
• Configure datastore(s)
• Restore VM files
• Re-IP network
• Start ESX server
• Restart VM
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VMware Site Recovery Manager (SRM)
• Maps LUNs to VMFS to (.vmdk and .vmx) files
• Automates• Procedures to monitor SAN-LUN replication• Processes to failover to hotsite• Procedures to re-IP networking at hotsite
• Storage supported replication agents• 3PAR, Compellent, Dell, EMC, FalconStor, Hitachi, HP, IBM,
LeftHand Networks, NetApp and Xiotech
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SRM Storage Replication Agents (RA)
• Provided by storage vendor
• RA is VMware defined API
• Provides consistent SRM services across storagevendors
• To initiate, monitor and terminate storagereplication
• Can support asynch and/or synchronous diskmirroring
• Can take advantage of storage snapshots
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SRM Datastore Groups
• Uses storage RAs to identifydatastore(s)/LUNs being replicated
• Identifies VMs mapped to datastore groups
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SRM Protection Groups
• Identifies VMs to be protected by SRM DR
• Must be associated with replicateddatastore groups
• Not all VMs in datastore group need to beprotected
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SRM Inventory Mapping
Maps protected VM:
• Replicated directories to remote sitedatastore(s)/LUNs
• VMs to remote site ESX servers
• Networking to remote site networking
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SRM Recovery Plan
Complete list of steps to recover protectedVMs:
• Can be pre-defined, e.g., PowerOnVM
• Can be customer defined using message steps
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SRM Limitations
• No failback support
• Need Virtual Center at both sites with SRMserver
• No support for RDM
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RDM VM DR
Same as Non-RDM VM DR but…
• RDM mapping files in VMFS needed
• Physical copy of RDM LUN(s) replicated to DRsite
• Storage HW configuration matches primary site
• No SRM support
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Non-VMware Replicator-Clustering Products
• VizionCore Vreplicator
• Uses software replication
• Double-take Server Recovery Option
• Uses software replication
• Veritas Cluster Services for VMware
• Uses storage HW replication
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Remote Data Replication Alternatives
• SAN (FC and iSCSI) data mirroring
• Archive/replication appliances
• Remote CDP
• Software replication
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SAN Mirroring Considerations
• Dedicated networking for FC, WAN for iSCSI
• Active storage at remote DR site
• Types of SAN mirroring
• Synch
• Semi-synch
• Asynch
• Requires matching vendor storage HW
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VMware SAN Mirroring Considerations
• Insure all LUNs for VMFS datastores aresingle consistency group
• Datastore(s) mirrored LUNs/volumes mustcontain all .vmdk and .vmx files for VMsneeded for DR
• RDM LUNs also need to be mirrored
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Archive/Replication Appliances
• Usually network attached dedicated HWproviding remote replication
• Can use TCP/IP over WAN for data transfer
• Support for Asynch mirroring
• Many archive appliances support remotereplication
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CDP Replication Appliances
Similar to archive/replication appliancesbut…
• Provide any point-in-time recovery
• Requires write-splitter
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Software Replication
• Double-take replication software forWindows
• Softek Replicator
• VizionCore Vreplicator
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Coldsite DR Considerations
• Backup data offsite• Could be image or file data
• H/W contracts for guaranteed deliverytimeframes
• S/W agreements for service and licensingin case of disaster
RTO: 8d..?
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Warmsite DR considerations
• Owned DR site or outsourced DR site
• For outsourced -- SunGard, IBM, HP, etc.
• Data can be at third site or located at DRsite
• Outsourced sites can be multiple locations
RTO:1d..8d
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Hotsite DR Considerations
• Asynch replication via SW, appliance or storagesubsystem
• Need to replicate datastores and RDM data
• S/W support -- Vreplicator and Double-Take SRO• No support for RDM data
• Dedicated networking
• Active data replication at DR site
RTO:3h..1d
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Mirror Site DR Considerations
• Dedicated SAN or appliance basedreplication
• Need to replicate datastores and RDM data
• Dedicated networking
• Active storage at DR site
RTO:0h..3h
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For More Information
• Disaster Recovery Journal, http://www.drj.com
• Business Continuity Journal,http://www.businesscontinuityjournal.com
• Continuity Central, http://www.continuitycentral.com
• Disaster Recovery Institute International,http://www.drii.org
• The Business Continuity Institute, http://www.thebci.org
• IT Disaster Recovery, http://www.itdr.info
• Uptime Institute, http://www.uptimeinstitute.org/
• SearchDisasterRecovery TechTarget website,http://searchdisasterrecovery.techtarget.com/
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For More Information
• Ray Lucchesi, President Silverton Consulting, Inc.,+1-720-221-7270 [email protected]://www.SilvertonConsulting.com
• Also at “Ask the Experts” session, 4:30pm to5:30pm in exhibition hall
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Some Terminology