VMware ESXi 6.0 CBT bug fix released

May 15, 2015May 15, 2015 VMware

You may remember ESXi 4.x-5.x had a CBT bug, as mentioned here, that could potentially cause your backups to be pretty useless. Well it seems ESXi 6.0 isn’t without it’s own CBT bug which could cause the following to possibly occur:

Backing up a VM with CBT enabled fails.
Powering on virtual machines fails.
Expanding the size of a virtual disk fails.
Taking VM quiesced snapshots fails.

Prior to the fix, the workaround was to disable CBT. Thankfully VMware has released a fix for the ESXi 6.0 CBT bug and it’s recommended that anyone who uses CBT apply this patch regardless if it was a clean install of VMware ESXi 6.0 or an upgrade to ESXi 6.0.

Installing ESXi 6.0 CBT Fix

The easiest method would to simply use VMware Update Manager to apply the patch (ESXi600-201505401-BG) to all of your hosts.

If you don’t have Update Manager installed in your environment you can also manually apply the patch to each of your hosts by following the below steps.

Download the ESXi600-201505401-BG patch from VMware.
Upload the patch (ESXi600-201505001.zip) to a datastore that each of your ESXi 6.0 hosts can access.
Place your host into maintenance mode, also enable SSH if it’s not already.

Connect to your host via SSH and type the following command:

esxcli software vib install -d "/vmfs/volumes/DATASTORENAME/ESXi600-201505001.zip"

Regardless if you install via Update Manager or SSH you will need to reboot the host.

Related Knowledge Base: KB2114076

vSphere 5.1 currently not compatible with any VMware View version

September 13, 2012September 13, 2012 VMware

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Before you go updating your vSphere to the new 5.1 version that was just released, VMware had just released this alert yesterday (9/12) that vSphere 5.1 is currently NOT compatible with any version of VMware View.

vSphere 5.1 is in the process of being certified against VMware View. We recommend that you do not upgrade vSphere above the supported versions listed in the VMware View 5.1 Release Notes.

For further updates and more information on this alert, refer to KB article:
vSphere 5.1 is not compatible with any versions VMware View (2035268).

If you don’t use VMware View, and are ready to upgrade to vSphere 5.1 be sure to check out the Installing vCenter Server 5.1 best practices from VMware.

VMware vCenter Server 5.5 Update 1b released

June 13, 2014 VMware

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VMware released vCenter Server 5.5 Update 1b today. The release does not bring any new features but instead patches a few bugs and possible security issues such as the heartbleed fix and most recent OpenSSL as mentioned in CVE-2014-0224. vCenter 5.5 Update 1b now includes the OpenSSL library which has been updated to versions openssl-0.9.8za, openssl-1.0.0m, and openssl-1.0.1h.

Another CBT bug found in VMware ESXi 6.0

November 12, 2015November 29, 2015 VMware

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VMware just published KB 2136854 regarding a new bug found in ESXi 6.0 that causes virtual machine backups, which use Changed Block Tracking (CBT), to be inconsistent. VMware says the cause of the issue is this:

This issue occurs due to an issue with CBT in the disklib area, this causes the change tracking information of I/Os that occur during snapshot consolidation to be lost. The main backup payload data is never lost and it is always written to the backend device. However, the corresponding change tracking information entries which occur during the consolidation task are missed. Subsequent QueryDiskChangedAreas() calls do not include these missed blocks, hence a backup based on this CBT data is inconsistent.

Improve Linux VM IO performance by disabling IO Scheduler

August 17, 2012March 6, 2017 VMware

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For a little while now we’ve been seeing RedHat Linux virtual machines performing poorly. Tasks would take considerably longer on the Linux VM’s then other Windows VM’s. After digging around I eventually found that RedHat has it’s own IO scheduler that runs in the background. On a physical box this wouldn’t be a big deal, but as a virtual machine everything is already being processed by VMware hypervisor. The fix, disable the IO Scheduler!

How to update VMware Windows VM’s DNS using PowerCLI

February 11, 2019August 26, 2019 VMware

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This post will show you how to update a VMware Windows virtual machine’s DNS IP addresses using PowerCLI.

You’ll also see how I went from a starting point to a fully working script – all thanks to the awesome #vCommunity!

Here at work we’ve been doing a number of networking, AD, and DNS changes. In doing so, our DNS IP address have changed. Changing the DNS settings for our workstations was easy, simply edit the DHCP scope.

The servers on the other hand all had static IP’s and static DNS IP’s entered, each of which needed to be updated.

How to fix VMware Converter error “FAILED: The VSS snapshots cannot be stored”

April 24, 2018 VMware

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While moving some VM’s from Hyper-V to VMware using VMware Converter a VM failed to convert with the error: FAILED: The VSS snapshots cannot be stored.

FAILED: The VSS snapshots cannot be stored because there is not enough space on the source volumes or because the source machine does not have any NTFS volumes. Error code: 2147754783 (0x8004231F).

Come to find out the System Reserved partition was full. Our soon to be retired Appassure backup application was nice enough to fill up the volume.

Luckily Appassure is being replaced by Veeam and fixing the above VMware Converter error is an easy fix.

Installing ESXi 6.0 CBT Fix

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