Cluster Shared Volumes Reborn in Windows Server 2012

1. WSV423 Cluster Shared Volumes Reborn in Windows Server 2012 Gareth James Hani Adhami Senior Consultant Senior Consultant

2. Agenda • Overview of Cluster Shared Volumes (CSV) • What’s changed in Windows Server 2012 • New CSV Architecture • Performance Enhancements • Improved Backup of Volumes

3. What are Cluster Shared Volumes (CSV)? • Clustered file system in Windows Server 2012 • Layer of abstraction above NTFS • Simultaneous access to CSV volume by multiple cluster nodes • LUN ownership abstracted from clustered application • Failover without drive ownership changes • No dismounting and remounting of volumes • Faster failover times (less downtime)

4. Flexibility • LUN - smallest unit of failover • Manageability • Multi-path • Masking several LUN’s Addresses Management ComplexityChallenges of Managing Hyper-V Clusters • Scalability • Complexity with drive letters • Capacity • Poor SAN space utilisation

5. Cluster Shared Volumes as you know it TodayWindows Server 2008 R2 • First introduced in Windows Server 2008 R2 • Only supported Hyper-V workload • Focused v1 release targeted at enabling Hyper-V • Implemented as file system mini-filter • Intercepted and routed I/O

6. CSV Motivations for Windows Server 2012 • Expand CSV to more workloads • File Server in addition to Hyper-V • Improve Backup • Improved performance • Direct I/O for more scenarios • Support for Spaces storage virtualisation • Multi-subnet support

7. New CSV ArchitectureWhat it delivers • Improved interoperability with file system mini-filter drivers • Better interoperability : Anti-virus software, Backup Software • Application consistent distributed backups • Removed external authentication dependencies • Improved performance and resiliency

8. New CSV Architecture Cont…. • Support for memory mapped files • Allows volume encryption • BitLocker encrypted volumes • Integrated with new File System features • Support for Offloaded Data Transfer (ODX) • Spot-fixing integrated to do online correction

9. Under the hood CSV Architecture

10. Cluster Shared Volumes (CSV)I/O Synchronisation Overview Metadata Simultaneous read/write access on all Cluster Nodes Server side metadata synchronisation - Avoids I/O interruptions Read/Write Shared Storage Shared LUN VHD VHD VHD

11. When do Metadata Updates Occur? • Virtual Machine • Creation/deletion • Power on/off • Mobility (live/storage migration) • Extending dynamic VHD • Renaming VHD • Backup - Snapshot creation

12. Coordination Node Node 1 Node 2 Node 3 CSVFS VM VM VM Share Share Share Server / SMB MUP/RDBSS/SMB MUP/RDBSS/SMB CSV File System Filter CSV Proxy File System CSV Proxy File System CSV Proxy File System NTFS CSV VolumeMgr CSV VolumeMgr Volume Manager CSV VolumeMgr LBFO/RDMA Disk Disk Storage Connection Broken or not present Direct I/O SAN

13. Simplified SetupConfiguring a CSV Disk • Failover Cluster Manager Storage view integration • “Cluster Shared Volumes” container removed • CSV integrated into Failover Cluster core feature • No longer needs to be explicitly enabled • Simply right-click to add to CSV – that’s it!

14. demo Setting up Clustered Shared Volumes

15. Single NamespaceConsistent view across the cluster • Single consistent file name space • Files have same name and path on any cluster node • Volumes exposed under “ClusterStorage” root directory • VolumeX directory name can be renamed

16. CSV NamespaceMount Points • Used custom reparse points in Win2008 R2 • Win2012 uses standard Mount Points • Delivers better interoperability with: • Performance Counters • System Center Operations Manager • Monitoring free space on CSV volumes • Better interoperability with backup software

17. CSV Proxy File System • CSV enabled volumes now appear as “CSVFS” • NTFS file system under the covers • Enables applications to be CSV aware • Ensures compatibility

18. Resiliency How CSV Enables Even Higher Availability

19. Fault Tolerant Application HandlesCSV Resiliency • CSV provides I/O fault tolerance • Transparently handles node, network, and HBA failures • CSVFS virtualises file handles to applications • Volume Paused - I/O queued • Reopens “true” files handles and remaps the “virtual” handles • Volume Resumed – I/O completed • Failover is transparent to application!

20. I/O Connectivity Fault Tolerance I/O Redirected via network VM running on Node 2 is unaffected Coordination Node SAN Connectivity Failure VM’s can then be live migrated to another node with zero client downtime VHD

21. Node Fault Tolerance New Coordinator Node Node Failure VM running on Node 2 is unaffected Coordination Node Brief queuing of I/O while volume ownership is changed Volume relocates to a healthy node VHD

22. Network Fault Tolerance Metadata Updates Rerouted to redundant network VM running on Node 2 is unaffected Volume mounted on Node 1 Network Path Connectivity Failure Fault-Tolerant TCP connections make a path failure seamless VHD

23. demo Cluster Shared Volume Resiliency

24. Performance Improved CSV Performance

25. Cluster Shared Volumes CachingImproved CSV I/O Performance • Windows Cache Manager integration • Buffered read and write I/O’s cached like traditional NTFS • CSV Block Cache • Read-Only cache for un-buffered I/O • Distributed cache consistent across cluster • Huge value for Pooled VM VDI scenarios • 512 MB recommended value • Disabled by default • No downtime to modify

26. demo Cluster Shared Volume Block Cache in action

27. Redirected I/O Less OftenCSV Optimisations • Direct I/O for more scenarios • Delivers faster I/O performance and lower network overhead • Direct I/O for all types of file opens • Buffered Reads and Writes • Better VM creation and copy performance • New algorithm for I/O redirection detection • Opportunistic Locking as distributed locking mechanism

28. Block Level I/O RedirectionHigh Performance fault condition I/O redirection VM VM Share Share Node 2 Node 1 Coordination Node CSVFS Server / SMB MUP/RDBSS/SMB CSV File System Filter CSV Proxy File System CSV Proxy File System Avoids traversing file system stack twice NTFS CSV VolumeMgr Volume Manager CSV VolumeMgr 2x performance over File System redirection LBFO/RDMA Disk Storage Connection Broken or not present

29. SMB 3.0 Performance ImprovementsInherit gains for CSV redirection performance • Improved Performance of refactored SMB 3.0 client (98%) • Network transport optimisations • TCP/IP – SMB multi-channel & NIC Teaming, TCP offloads, DC-TCP • RDMA – Lowest network CPU overhead (cycles/byte)

30. High Speed CSV I/O RedirectionSMB 3.0 integration • SMB multi-channel • Traffic streamed across multiple networks • Improved I/O performance in redirected mode • SMB Direct (SMB 3.0 over RDMA) VM with I/O being redirected Coordinator Node 10.10.10.X 20.20.20.X CSV Streaming I/O Across Multiple Networks VHD

31. Performance Improvements – RecapCSV Redirected mode enhancement summary Many Pieces Come Together for Radical Improvement

32. Deployment CSV Deployment Considerations

33. Basic disk Formatted with NTFS file system FAT / FAT32 / ReFS not supported CSV enabled disk cannot be used as a Witness Disk (aka. quorum disk) Can be basic or a Space Simple Space Mirrored Space with block level Redirected I/O Parity Space not supported Cannot have Windows Dedup enabled CSV RequirementsThe requirements to enable a disk to be CSV

34. Planning VM Density Per CSV VolumeDeployment considerations • How many VMs per CSV volume? • No CSV volume restrictions • VMFS limitations do not apply to CSV • CSV volume Metadata updates orchestrated server side and parallelised How many IOPS can your storage array handle?

35. Backup CSV Backup

36. CSV Backup Key Wins • Distributed Snapshots • Distributed app consistent snapshot creation across cluster • Parallel Backups • On same or different • CSV volumes • Cluster nodes • Improved Interoperability • Backup applications / requestors not required to be ‘CSV aware’ • With filter drivers • Non-disruptive backups • CSV volume ownership does not change during backup • Improved I/O performance • Direct I/O mode for software snapshots

37. SummaryKey Takeaways • CSV significantly enhanced in Windows Server 2012 • Support for more workloads • High performance • Name a concern, it’s gone! • CSV is a core infrastructure to enable your private cloud INFRASTRUCTURE as a SERVICE

38. Related Content • Breakout Sessions (session codes and titles) • VIR312 - What's New in Windows Server 2012 Hyper-V, Part 1 • VIR315 - What's New in Windows Server 2012 Hyper-V, Part 2 • VIR314 - WS2012 Hyper-V Live Migration and Live Storage Migration • WSV326 - The Path to Continuous Availability with WS2012 • WSV332 - Cluster-Aware Updating and the New Generation of WSUS Find Us Later At the ‘Speaker Lounge’ (12:45 – 13:45)

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