Tag Archives: vSAN

Critical Patch for All-Flash vSAN with Deduplication (6.0 and 6.5)

VMware has released a critical patch for vSAN 6.0 and 6.5. This patch contains a fix for a highly critical vSAN issue that might cause IO read errors and in some cases severe symptoms such as inaccessible VMs, host failures, or stuck resyncs. The issue manifests itself only under highly specific operations and IO patterns.

The bug only affects All-Flash vSAN configurations with deduplication enabled.

Symptoms for this issues are the following messages in the Events tab:

  • "vSAN detected an unrecoverable medium or checksum error for component uuid on disk group uuid."
  • "vSAN detected and fixed a medium or checksum error for component uuid on disk group uuid."

The following versions are affected according to KB2151042 and KB2151081.

Name Patch Date Build
ESXi 6.5 Update 1 ESXi650-update1 2017-07-27 5969303
ESXi 6.5 Update 1 (Security only) ESXi650-update1 2017-07-27 5969300
ESXi 6.5d (vSAN 6.6 Patch) ESXi650-201704001 2017-04-18 5310538
ESXi 6.5 Express Patch 1a ESXi650-201703002 2017-03-28 5224529
ESXi 6.5 Patch 1 ESXi650-201703001 2017-03-09 5146846
ESXi 6.5 Patch 1 (Security Only) ESXi650-201703001 2017-03-09 5146843
ESXi 6.5a ESXi650-201701001 2017-02-02 4887370
ESXi 6.5 GA 2016-11-15 4564106
ESXi 6.0 Update 3a (Patch 5) ESXi600-201706001 2017-06-06 5572656
ESXi 6.0 Update 3a (Patch 5) (Security Only) ESXi600-201706001 2017-06-06 5485776
ESXi 6.0 Express Patch 7a ESXi600-201703001 2017-03-28 5224934
ESXi 6.0 Update 3 ESXi600-update3 2017-02-24 5050593
ESXi 6.0 Update 3 (Security Only) ESXi600-update3 2017-02-24 5047589
ESXi 6.0 Patch 4 ESXi600-201611001 2016-11-22 4600944
ESXi 6.0 Patch 4 (Security Only) ESXi600-201611001 2016-11-22 4558694

VMware states that all vSAN customers using All-Flash with deduplication enabled must upgrade to this patch immediately:

vSAN 6.6 RVC Guide Part 6 - Troubleshooting

vSAN 6.6 RVC Guide

The "vSAN 6.6 RVC Guide" series explains how to manage your VMware Virtual SAN environment with the Ruby vSphere Console. RVC is an interactive command line tool to control and automate your platform. If you are new to RVC, make sure to read the Getting Started with Ruby vSphere Console Guide. All commands are from the latest vSAN 6.6 version.

The sixth part is about troubleshooting vSAN deployments.

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vSAN 6.6 RVC Guide Part 5 - Performance Service

vSAN 6.6 RVC Guide

The "vSAN 6.6 RVC Guide" series explains how to manage your VMware Virtual SAN environment with the Ruby vSphere Console. RVC is an interactive command line tool to control and automate your platform. If you are new to RVC, make sure to read the Getting Started with Ruby vSphere Console Guide. All commands are from the latest vSAN 6.6 version.

In the fifth part, I'm working with commands related to the vSAN performance service. These commands are used to enable and configure the vSAN Performance Service and gather performance related information.

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vSAN 6.6 RVC Guide Part 4 - Cluster Health

vSAN 6.6 RVC Guide

The "vSAN 6.6 RVC Guide" series explains how to manage your VMware Virtual SAN environment with the Ruby vSphere Console. RVC is an interactive command line tool to control and automate your platform. If you are new to RVC, make sure to read the Getting Started with Ruby vSphere Console Guide. All commands are from the latest vSAN 6.6 version.

In the fourth part, I'm working with commands related to the vSAN health plugin. These commands are only available when the Health Services are installed.

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vSAN 6.6 RVC Guide Part 3 - Object Management

vSAN 6.6 RVC Guide

The "vSAN 6.6 RVC Guide" series explains how to manage your VMware Virtual SAN environment with the Ruby vSphere Console. RVC is an interactive command line tool to control and automate your platform. If you are new to RVC, make sure to read the Getting Started with Ruby vSphere Console Guide. All commands are from the latest vSAN 6.6 version.

The third part explains commands related to the object management in vSAN. These commands are used for troubleshooting or reconfiguration of objects. They also provide an insight on how vSAN works.

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vSAN 6.6 RVC Guide Part 2 - Cluster-Administration

vSAN 6.6 RVC Guide

The "vSAN 6.6 RVC Guide" series explains how to manage your VMware Virtual SAN environment with the Ruby vSphere Console. RVC is an interactive command line tool to control and automate your platform. If you are new to RVC, make sure to read the Getting Started with Ruby vSphere Console Guide. All commands are from the latest vSAN 6.6 version.

The second part explains commands related to vSAN cluster administration tasks. These commands are required to gather information about ESXi hosts and the cluster itself. They also provide important information when you want to maintain your vSAN cluster or configure a stretched cluster:

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vSAN 6.6 RVC Guide Part 1 - Basic Configuration

vSAN 6.6 RVC Guide

The "vSAN 6.6 RVC Guide" series explains how to manage your VMware Virtual SAN environment with the Ruby vSphere Console. RVC is an interactive command line tool to control and automate your platform. If you are new to RVC, make sure to read the Getting Started with Ruby vSphere Console Guide. All commands are from the latest vSAN 6.6 version. The first part explains basic configuration tasks that are required for the initial setup:

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How to silence VMware vSAN Health Checks

A new feature in vSAN 6.6 is the ability to silence Health Checks. In previous versions, it was already possible to disable alerts that are triggered by health checks. Silencing health checks is one step further and enables you to have a clean vSAN health. Silenced checks are displayed with a green checkmark and are marked as "Skipped".

Especially for home labs, where unsupported hardware is used, this is a great feature.

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vSAN 6.6 vMotion Basic Unicast Connectivity Health Check Fails

After upgrading my lab to vSAN 6.6, I noticed that the newly introduced vMotion health check (vSAN Cluster > Monitor > vSAN > Health > Network) showed up as failed for the following checks:

  • Failed - vMotion: Basic (unicast) connectivity check
  • Failed - vMotion: MTU check (ping with large packet size)

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VMware vSAN 6.6 Upgrade Steps

The VMware vSAN 6.6 has been released today. In this post, I am going to run through the 3 steps to upgrade vSAN 6.5 to vSAN 6.6. Upgrading Virtual SAN is a multistage process, in which you must perform the upgrade procedures in the order described here:

  1. Upgrade vCenter Server to version 6.5.0d
  2. Upgrade ESXi Hosts to version 6.5.0d
  3. Upgrade the vSAN on-disk format to version 5.0

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