Tuesday, September 1, 2015

vSphere Fault Tolerance - Redundant Storage

vSphere Fault Tolerance (FT), one of the most cool and less implemented feature of VMware vSphere had a significant improvement on vSphere 6, at this point you probably know what FT is about, just in case you don’t know yet, here’s a brief explanation: 

FT is a feature that enables you to protect your mission critical applications creating a secondary VM and keep them synchronized, so in case of a failure of the primary VM the secondary VM will take place almost instantly. Cool right ?!?


Problem was, until vSphere 5.5, you could only protect VMs with a single vCPU !!! Good luck finding a mission critical VM running with a single vCPU.

As you could imagine, support for multiple vCPUs VM has been asked for years and finally on vSphere 6 it’s now possible.

But this post is not to talk about FT on multiple vCPUs, there is a bunch of blogs about it already, I wanna talk about another new resource of FT, Redundant Storage.

Now with vSphere 6 you have the option to also replicate the data to another datastore, eliminating the single point of failure that datastores has been being so far.


 FT will create a secondary copy of vmdk, vmx and the Tie Breaker file on a separate datastore and keep the data synchronized between them, so in case of a datastore failure the secondary VM will take place without any problem.


There's not trick to use it, just Turn On Fault Tolerance on the VM.



Then browse for the datastore where will want to place each file.

FT is a precious and limited resource, be aware of it’s limitation of 4 VMs per host or 8 vCPUs, on this sum take into account primary and secondary VMs.


Are you willing to use FT more often now ???



MouradN said...

Good explanantion. Short and straight forward. Thanks for your time, mate!

Wednesday said...

Perfect explanation. Haven't used FT feature before

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I’m an IT specialist with over 15 years of experience, working from IT infrastructure to management products, troubleshooting and project management skills from medium to large environments. Nowadays I'm working for VMware as a Consulting Architect, helping customers to embrace the Cloud Era and make them successfully on their journey. Despite the fact I'm a VMware employee these postings reflect my own opinion and do not represents VMware's position, strategies or opinions. Reach me at @dumeirell

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