VMware Virtual SAN

Duncan Epping

Chief TechnologistOffice of the CTOStorage & Availability

Hyper-converged infrastructure software

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Agenda

1 Introduction

2 Virtual SAN, what is it?

3 Virtual SAN, a bit of a deeper dive

4 Virtual SAN Recent Enhancements

5 Wrapping up

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The Software Defined Data Center

Compute Networking Storage

Management

• All infrastructure services virtualized: compute, networking, storage

• Underlying hardware abstracted, resources are pooled

• Control of data center automated by software (management, security)

• Virtual Machines are first class citizens of the SDDC

• Today’s session will focus on one aspect of the SDDC - storage

Hardware evolutionstarted the storage revolution

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Simplicity: Operational / Management

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The Hypervisor is the Strategic High Ground

SAN/NASx86 - HCI Object Storage

VMware vSphere

Cloud Storage

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Storage Policy-Based Management – App centric automation

Overview• Intelligent placement

• Fine control of services at VM level

• Automation at scale through policy

• Need new services for VM?• Change current policy on-the-fly

• Attach new policy on-the-fly

Virtual Machine Storage policyReserve Capacity 40GB

Availability 2 Failures to tolerate

Read Cache 50%

Stripe Width 6

Storage Policy-Based Management

vSphere

Virtual SAN Virtual Volumes

Virtual Datastore

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Storage Policy Based Management – What does it look like?

If the storage can satisfy the VM Storage Policy, the VM Summary tab in the vSphere client will display the VM as compliant.

If not, either due to failures, lack of resources or other reasons, the VM will be shown as non-compliant.

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Virtual SAN,what is it?

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Virtual SAN, what is it?

Hyper-Converged Infrastructure

Distributed, Scale-out Architecture

Integrated with vSphere platform

Ready for today’s vSphere use cases

Software-Defined Storage

vSphere & Virtual SAN

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But what does that really mean?

VSAN network

Generic x86 hardware

VMware vSphere & Virtual SAN Integrated with your Hypervisor

Leveraging local storage resources

Exposing a single shared datastoreVirtual SAN

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VSAN is the Most Widely Adopted HCI Product

Simplicity is key, on an oil platform there are no

virtualization, storage or network admins. The infrastructure is

managed over a satellite link via a centralized vCenter Server.

Reliability, availability and predictability is key.

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Virtual SAN Use Cases

VMware vSphere + Virtual SAN

End User Computing Test/Dev

ROBOStagingManagementDMZ

BusinessCritical Apps DR / DA

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Broadest Deployment Options from HCI to SDDC Built on Industry-Leading VMware Hyper-Converged Software (HCS)

Certified Solutions Engineered Appliances

Virtual SAN Ready Nodes

EVO SDDC

Certified PartnerHardware

NSX

vRealize

Lifecycle Management

EMC Federation HCI Appliance

VMware HCSVirtual SAN + vSphere + vCenter

VMware HCSVirtual SAN + vSphere + vCenter

VMware HCSVirtual SAN + vSphere + vCenter

EVO SDDC Manager

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Tiered Hybrid vs All-FlashAll-Flash

100K IOPS per Host+

sub-millisecond latency

Caching

Writes cached first,Reads from capacity tier

Capacity TierFlash Devices

Reads go directly to capacity tier

SSD PCIe Ultra DIMM

DataPersistence

Hybrid

40K IOPS per Host

Read and Write Cache

Capacity TierSAS / NL-SAS / SATA

SSD PCIe Ultra DIMM

Virtual SAN

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Really Simple Setup

Deduplication and

Compression Enable?

Fault Domains, 2 node or stretched cluster?

Manual or Automatic Disk

Claiming

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Virtual SAN, a bit of a deeper dive

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Virtual Machine as a set of Objects on VSAN

• VM Home Namespace

• VM Swap Object

• Virtual Disk (VMDK) Object

• Snapshot (delta) Object

• Snapshot (delta) Memory Object

VM Home

VM Swap

VMDK

Snap delta

Snap memorySnapshot

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Define a policy first…Virtual SAN currently surfaces multiple storage capabilities to vCenter Server

What If APIs

New Capabilities in VSAN 6.2

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ESXi Host

Virtual SAN Objects and ComponentsVSAN is an object store!• Object Tree with Branches

• Each Object has multiple Components– This allows you to meet availability and

performance requirements

• Here is one example of “Distributed RAID” using 2 techniques:– Striping (RAID-0)– Mirroring (RAID-1)

• Data is distributed based on VM Storage Policy

ESXi HostESXi Host

Mirror Copy

stripe-2b

stripe-2a

RAID-0

Mirror Copy

stripe-1b

stripe-1a

RAID-0

witness

VMDK Object

RAID-1

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Number of Failures to Tolerate/Failure Tolerance Method• Defines the number of hosts, disk or network failures a storage object can tolerate.

• RAID-1 Mirroring used when Failure Tolerance Method set to Performance (default).

• For “n” failures tolerated, “n+1” copies of the object are created and “2n+1” host contributing storage are required!

esxi-01 esxi-02 esxi-03 esxi-04

Virtual SAN Policy: “Number of failures to tolerate = 1”

vmdk

~50% of I/O

vmdk witness

~50% of I/O

RAID-1

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Assign it to a new or existing VMWhen the policy is selected, Virtual SAN uses it to place / distribute the VM to guarantee availability and Performance

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Fault Domains, increasing availability through rack awareness• Create fault domains to increase availability

• 8 node cluster with 4 defined fault domains (2 nodes in each)

FD1 = esxi-01, esxi-02 FD3 = esxi-05, esxi-06

FD2 = esxi-03, esxi-04 FD4 = esxi-7, esxi-08

• To protect against one rack failure only 2 replicas are required and a witness across 3 failure domains!

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FD2 FD3 FD4

esxi-01

esxi-02

esxi-03

esxi-04

esxi-05

esxi-06

esxi-07

esxi-08

FD1

vmdk vmdk witness

RAID-1

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Virtual SAN,Recent Enhancements

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VSAN 5.5March 2014

VSAN 6.0March 2015

All Flash Configuration64 node VSAN clusterx2 Hybrid PerformanceVSAN Snapshots/ClonesHealth UIRack Awareness

VSAN 6.2March 2016

Deduplication and CompressionRAID 5/6 support

Software ChecksumQoS via IOPS Limits

IPv6Performance Service

Enhanced Capacity Views

VSAN 6.1September 2015

Stretched Cluster Replication - 5 Minutes RPO2-node ROBOHealth Monitoring & Remediation

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Virtual SAN – Stretched ClusterActive-Active data centers

• Virtual SAN cluster split across 2 sites!

• Each site is a Fault Domain (FD)

• Site-level protection with zero data loss and near-instantaneous recovery

• Support for up to 5ms RTT latency between data sites– 10Gbps bandwidth expectation

• Witness VM can reside anywhere– 200ms RTT latency– 100Mbps bandwidth required at most

• Automated failover5ms RTT, 10GbE

Today

VMware vSphere & Virtual SAN

vSphere

witness

vmdk vmdk

witness

Any dist

ance >

5 min RPO

vSphere & Virtual SAN

Site Recovery Manager

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Advanced Troubleshooting with VSAN Health Check

• Cluster Health• Network Health• Data Health• Limits Health• Physical Disk Health

• Stretched Cluster

• Proactive Tests

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Virtual SAN 6.2specifics

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Deduplication and Compression for Space Efficiency• Nearline deduplication and compression per disk group level.

– Enabled on a cluster level– Deduplicated when de-staging from cache tier to capacity tier– Fixed block length deduplication (4KB Blocks)

• Compression after deduplication– If block is compressed <= 2KB– Otherwise full 4KB block is stored

Beta

esxi-01 esxi-02 esxi-03

vmdk vmdk

vSphere & Virtual SAN

vmdk

All Flash OnlyNew

in

6.2

Significant space savings achievable, making the economics of an all-flash

VSAN very attractive

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RAID-5/6 (Inline Erasure Coding)• When Number of Failures to Tolerate = 1 and Failure Tolerance Method = Capacity RAID-5

– 3+1 (4 host minimum)– 1.33x overhead for RAID-5 instead of 2x compared to FTT=1 with RAID-1

• When Number of Failures to Tolerate = 2 and Failure Tolerance Method = Capacity RAID-6– 4+2 (6 host minimum)– 1.5x overhead for for RAID-6 instead of 3x compared to FTT=2 with RAID-1

RAID-5

ESXi Host

parity

data

data

data

ESXi Host

data

parity

data

data

ESXi Host

data

data

parity

data

ESXi Host

data

data

data

parity

New in

6.2All Flash Only

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Software Checksum and disk scrubbing

Overview• End-to-end checksum of the data to detect and resolve silent

disk errors due to faulty hardware/firmware• Checksum is enabled by default (policy driven)• If checksum verification fails on a read:

– VSAN fetches the data from another copy in RAID-1– VSAN recreates the data from other components in RAID-5/6

stripe• Disk scrubbing is run in the background

Benefits• Provide additional level of data integrity• Automatic detection and resolution of silent disk errors

New in

6.2

Virtual SAN Datastore

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Other new improvementsNew

in

6.2

Client Cache• Write through read memory cache

– 0.4% of total host memory, up to 1GB per host• “Local” to the virtual Machine• Low overhead, big impact!

Sparse Swap• Reclaim Space used by memory swap• Host advanced option enables setting policy for swap to

no space reservation

IOPS limit on object• Policy driven capability• Limit IOPS per VM/Virtual Disk• Eliminate noisy neighbor issues• Manage performance SLAs

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Enhanced Virtual SAN Management with New Health Service

Built-in performance monitoringHealth and performance APIs and SDK

Storage capacity reportingAnd many more health checks…

Performance Monitoring Capacity Monitoring

New in

6.2

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Performance, Scale and Availability for Any ApplicationNew

in

6.2

B U S I N E S S - C R I T I C A L A P P L I C AT I O N S

SAP Core Ready

Testing and validated deployments

SAP

Tightly integrated cloud management

Bundles Virtual SAN licenses for lowestcost VDI storage

Horizon

Oracle RAC supported

Testing and validated deployments

Oracle

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Wrapping up

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VMware Virtual SAN: Generic Object Storage Platform

VMware vSphere

Virtual SAN

VMFS Block File Rest

Vision