Summary of "What is VMware vSAN? - vSAN 101 \\ Part 1"

Summary of “What is VMware vSAN? - vSAN 101 \ Part 1”

This video is an introductory guide to VMware vSAN, focusing on explaining its core concepts, architecture, and features. It is part one of a multi-part series that will cover basics, setup, management, and storage policies in detail.

Key Technological Concepts and Product Features

VMware vSAN Overview

vSAN is enterprise storage virtualization software integrated into the ESXi hypervisor.
It enables the creation of a shared storage pool by aggregating local or direct-attached storage devices across multiple servers.
Eliminates the need for traditional shared storage like Fibre Channel SANs, simplifying storage infrastructure.

vSAN Architecture

Supports Hyperconverged Infrastructure (HCI), combining compute, storage, and networking virtualization in one platform.
Storage is pooled from multiple hosts into a single vSAN datastore visible to all hosts in the cluster.
Uses an object-based file system, where VM components (virtual disks, snapshots, swap files) are treated as objects distributed across disks and hosts.

Disk Groups and Storage Tiers

Traditional vSAN uses a two-tier architecture:
- Cache Tier: SSD or NVMe drives used for caching (write buffer and read cache).
- Capacity Tier: Magnetic (spindle) or SSD drives used for data storage.
Disk groups consist of one cache device and up to seven capacity devices.
Each host can have up to five disk groups.
Hybrid (SSD + HDD) and All-Flash configurations are supported:
- Hybrid: cache is SSD, capacity is HDD.
- All-Flash: both cache and capacity tiers use SSD/NVMe, with cache handling 100% of writes.

vSAN Networking Requirements

Requires a dedicated network for vSAN traffic.
Hybrid setups can use 1 Gbps NICs; all-flash setups require at least 10 Gbps NICs (preferably 25 Gbps or higher in vSAN 8).
Supports standard or distributed vSwitches; distributed switches are recommended for better traffic management with Network IO Control.

vSAN Ready Nodes and Hardware Compatibility

VMware certifies specific hardware configurations as “vSAN Ready Nodes.”
Production environments should use certified hardware for support and stability.
vSAN 8 introduces Express Storage Architecture (ESA), a new single-tier architecture eliminating cache tier and disk groups, supporting only SSDs, and requiring higher network speeds (25 Gbps+).
ESA is currently Greenfield only (no upgrade path from older versions).

Deployment Models

Single Site Cluster: Minimum 3 hosts pooling local storage into one vSAN datastore.
Two-Node Cluster: For small or branch office setups, requires a witness appliance to provide quorum.
Stretched Cluster: vSAN datastore spans two geographically close sites with a third site hosting a witness for quorum and disaster tolerance.

Storage Policies

vSAN uses storage policies to define VM storage requirements such as fault tolerance, encryption, deduplication, compression, etc.
Policies control how data is protected and stored across the cluster.
Key parameters include:
- Failures to Tolerate (FTT): Number of host/disk failures the VM can withstand.
- Site Disaster Tolerance: For multi-site deployments (stretched clusters).
Common FTT options:
- FTT=0: No redundancy (RAID 0).
- FTT=1: Mirroring with two copies (default).
- FTT=2 or 3: Higher levels of mirroring for increased fault tolerance.
- RAID-5/RAID-6 (Erasure Coding): More space-efficient fault tolerance requiring more hosts (4 for RAID-5, 6 for RAID-6), but with potential write performance impact.

Fault Tolerance and Data Redundancy

vSAN distributes VM data components and witness components across hosts to maintain quorum and availability.
Witness components act as tiebreakers in case of failures or network partitions.
HA (High Availability) can restart VMs on surviving hosts if a host fails, as long as data remains accessible.

Performance and Capacity Considerations

Mirroring uses more storage space but offers better write performance.
RAID-5/6 saves space but involves parity calculations that can degrade write performance.
Cache device failure in a disk group can cause the entire disk group to go offline, so multiple disk groups per host can improve resilience.

Guides, Tutorials, and Upcoming Content

Future videos in the series will cover:

Step-by-step vSAN setup and configuration.
Detailed management and monitoring of vSAN.
In-depth tutorials on storage policies and their application.
Troubleshooting and drive replacement procedures.

The presenter will demonstrate network setup (VMkernel ports for vSAN traffic) and policy creation in upcoming videos.

Main Speaker / Source

Stephen (channel owner/presenter) — Provides the explanation, walkthrough, and technical insights throughout the video.

This video serves as a foundational overview for IT professionals or VMware administrators new to vSAN, explaining the technology’s purpose, architecture, deployment options, and storage management principles.

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Summary of "What is VMware vSAN? - vSAN 101 \\ Part 1"