Just be sure to check the Matrix so that everything is still compatible
It's recommended to upgrade vCenter first, then the ESXi and then Horizon to avoid any incompatibilities and cause any outages.
Hope that helps
Yes, you are correct as that as your upgrade for vCenter and ESXi,
ESXi 5.5u3 > 6.0u3
Composer 6.2.3 to 7.X
Connection Servers 6.2.3 to 7.X
Then vCenter 6.0u3 to 6.X
Check physical ESXi servers to check the version of ESXi that can be run on them.
Ok, I will try this path. One more question I have now vCenter on Windows with external MSSQL, can I migrate to vCSA when I update 6.0 to 6.0u3 or I should wait and migrate to vCSA on the end? Or maybe I should stay with the Windows vCenter?
Ok, i check but vCenter 6.0u3 and esxi 6.0u3 support Horizon in all version, and vCenter 6.7u1 not support Horizon 6 and I cannot upgrade vCenter to newest version. That's why I want to upgrade to version 6.0u3, then horizona to the newest version because it is entered and I will later update to the latest version of vCenter and esxi. Are there any contraindications to do that?
That's what I was trying to state but wasn't the clearest. Upgrade to latest vCenter and ESXi after Horizon is on 7.X
Just make sure you look at VMware Compatibility Guide - System Search to make sure your you know what is the latest supported version of ESXi on your hardware.
I would wait till the end, the tool to do this has got a lot better in 6.7.
But if you have Composer co-installed with the Windows vCenter you need to move that to a new VM before you do the conversion.
What does your environment looks like in terms of virtual desktops? If it's relatively simple I would build a new 6.7 VCSA with Horizon 7.x and then migrate over.