When you first deploy a Horizon desktop pool onto Horizon it will create a number of policies that it will apply to the desktops.

In Horizon 6 the policy applied to Floating Clones (Linked or Full) had a Failure to Tolerate of 0.  The rationale is that Floating Clones are volatile and it doesn’t matter if they are lost, which is fairly reasonable. The impact though was if a host failed, it would loose all VMs running on that host AND all VMs with their storage on that host which could cause a significant outage.   Since the size of the delta disks is relatively small and not a constraining factor I usually recommended increasing the FTT to 1.

Now in Horizon 7 this has become the default policy! If you upgrade a Horizon 6 environment to Horizon 7 it will not update the existing policy, but you can change the FTT to 1 even if running Horzion 6 and it will never override that. But if you are deploying a greenfield Horizon 7 environment it will deploy linked clones with an FTT of 1.  But of course you can change this to 0 if you want to reduce storage consumption at the risk of losing desktops in host failures.

Below is an overview of the default policies in Horizon 7.