Virtual SAN

Virtual SAN Overview

• Virtual SAN is built right into the ESXi hypervisor.• No virtual appliance or agents to install or setup.

• RAIN (Redundant Array of Independent Nodes) Architecture• Essentially RAID-5 by default with server nodes.

• Easy Setup and Configuration• Configuration can be setup in mins without agents or additional

software.

• Uses storage profiles on a per VM/VMDK level• Can be managed at a VMDK level. 2

VSAN Example Diagram

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Host Requirements

• Minimum of 3x ESXi 5.5 hosts required

• Maximum of 32 ESXi hosts• NOT all hosts have to have storage to contribute to the VSAN

cluster.

• Additional Virtual SAN License Required (Not included in Ent.+)• Two Licensing Tiers with or without Data Protection

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Network Requirements

• Needs a dedicated Layer-2 network• VLAN logical isolation should work

• Multicast must be enabled (IGMP Snooping)

• Requires additional dedicated 10Gbps links

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Storage Requirements

• Typical SAS or SATA RAID or non-RAID HBA or controller

• What is the total needed capacity of the datastore?• Specifically Virtual Machine Files (VMDK, SWAP, Snapshots, etc…)

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Storage Constraints

• Disk Groups:• 1x SSD and 1x disk minimum per disk group• 1x SSD and 7x disks maximum per disk group• No More than 5 disk groups per host

• SSD Devices:• Does NOT contribute to the usable capacity of the clustered

datastore• Only used for the READ caching and WRITE buffering• By default, 70% is allocated for READ caching, 30% for WRITE

buffering

• Magnetic/Spinning Disks:• Contributes to the usable capacity of the clustered datastore

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How Virtual SAN Scales

• Storage Capacity:• Add more disks to the disk group (Scale Up) – Minimal• Add more disk groups (Scale Up) – Moderate• Add more hosts to the cluster (Scale Out) – Optimal

• Storage Performance:• Add more disks to the disk group (Scale Up) – Minimal• Add more disk groups (Scale Up) – Moderate• Add more hosts to the cluster (Scale Out) – Optimal

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Virtual SAN Scale Example

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Now Supports up

to 32 Hosts!!!

Virtual SAN Limitations

• Virtual disks must be < 2-512b TB in size

• Does not support Fault Tolerance, DPM, or SIOC

• Datastore heartbeats are disabled on VSAN datastores

• Disks that participate in the VSAN storage are fully allocated for only VSAN

• 100 VMs per Host or 3200 VMs (or 2048 for HA protected) per cluster

• Hosts with 512GB+ RAM require ESXi to be installed on a magnetic disk

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Virtual SAN Best Practices

• Uses typical HBA/disk controller (do NOT use RAID, setup in pass-through)

• Multiple 10Gbps network connectivity for failover (redundancy)• The use of jumbo frames on the Virtual SAN network• SSD to disks ratio of a minimum of 1:10 or greater• To increase performance add more disk groups• Install ESXi on a USB/SD device and use the ESXi Dump Collector

service• Uniform HW configs help avoid variations in perf and reduces

complexities• Use 4x hosts minimum to allow proper protection during

maintenance11

Virtual SAN Node Costs

Hardware:

Dell R920 Host - $120,000•4x Intel Xeon E7-8891 v2 Processor 3.2GHz•1TB of RAM (32x LRDIMM 1600 MT/s Low Volt Quad Rank)•2x FusionIO ioDrive2 3TB MLC PCIe•2x Intel X520 DP 10Gbps NICs•1x Intel Ethernet I350 QP 1Gb Network

Software:•VMware ESXi 5.5 Enterprise Plus - $4,000•VMware Virtual SAN license w/Data Protection - $12,000

Approx. $136,000 /each node*(assuming network gear is already provided) 12

Virtual SAN References

• Virtual SAN: Scaling Storage Capacity• Virtual SAN: Design and Sizing Guide• Virtual SAN: Sizing Tool • Virtual SAN: FusionIO Reference Architecture - FusionIO• Virtual SAN: Duncan Epping’s Virtual SAN Links• Virtual SAN: VMware Feature Walkthrough• vSphere 5.5 Documentation: Working with Virtual SAN• VMworld 2013: Session STO5391 - VMware Virtual SAN (VSAN)

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