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 Solutions Architect, helping customers to embrace the Cloud Era and make them successful on their journey. Although I'm a VMware employee, these postings reflect my opinion and do not represent VMware's position, strategies or opinions. Reach me at @dumeirell
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.