Noob Question on VMWare VCenter and reinstalling server...

[IdahoTech]

Hello everyone,

I am somewhat in a quandary here and need some help. I want to just say out front I am not a newbie to the world of VM, but I am a noob in the terms that I wear many hats like everyone here as well as being the Sr. IT Tech and still have to do work orders, move cable, computers, troubleshoot many systems in our district, etc...So overwhelmed would probably be best to describe it here. Over the past few years we have been piecing together our VMWare Environment (due to us being a school district with limited funds). Let me give you the short of it:

1 VMWare VCenter server on 200GB of a 9 TB system.

6 Vmware ESXi servers running different version of VMWare...from 4.0 to 5.5 rev b.

Here is my problem. I want to upgrade all my systems to the newest VMWare 6.x as well as VCenter.

I used to have a iSCSI setup and created iSCSI drives on the rest of the 9TB's on the VCenter server and linked them to other systems. Then after a power outage we lost our our iSCSI and I had to recreate it and after some time thought about it and made the decision to Move all the VM's to their appropriate servers, leaving the 2 iSCSI 2tb drives unused on the VCenter server as well as 4.5TB unallocated.

The reason for the mess above is we had heard that if you run iSCSI and the system goes down and you loose  the connection to the iSCSI it is like pulling the plug on a running drive thus loosing all your VM's. I believe, though, once I get this all in place it will make life a lot easier.

Here are my questions:

1. Can I totally destroy the VCenter server reload it with the latest VCenter Server software (on a smaller server) without damage to the running VM's on the ESXi Servers?

2. I have two servers that have 9TBs of storage (the VCenter server and my 5.5 ESXi server with my main vms) and would like to run them together with a new Synology DS1815+ with 27TB (7, 6TB drives in Raid 6) as a backup offsite, is this possible?

3. Would I be better off using the VMWare backup, snapshot, etc. or would it be wise to purchase a 3rd party backup system like Veeam to help make the off site backup?

We own our Fiber ring in district and just put in switches that have 10gb capability. I have had a couple of other tech's tell me that a iSCSI should be on its own separated network to keep the chatter down. Is this really necessary with the speeds of today? If it is all in the serer room and hooked with either multiple 1GB connections or through 10GB connections?

And the offsite backup would be hooked to either the Fiber connection or through one of the 10GB ports in our ring as well as battery backup etc to ensure the system running properly, but need to know if I really need to make the iSCSI on its own network?

If anyone has any questions please do not hesitate to ask. I am self taught (videos, Reading, Doing, School of Hard Knocks, etc...) but can grasp just about anything if in layman terms. I have had training on some things, but not on VMWare. I had to do that one the hard way and learn as you go.

I do appreciate anyone who takes the time to read this and please if any questions please do not hesitate to ask,just please be kind, I know I am no expert and just ask for help in this mess to get it running smoothly.

Thanks for your time in the matter.....

Jim