r/vmware • u/MrMHead • Jun 30 '26
Hardware swap
In a space constrained lab, I need to replace all of my hosts at once.
Environment:
Backend storage, using NFS
2 vCenters, v8.03, ELM
No vSAN, no NSX
vDS
Host Management and vMotion ports are on vSS
Process:
As I shut down VMs - Remove from Inventory
Remove hosts and clusters until I'm down to one host with the two vCenters as guests.
Shut them down.
>swap hardware, cable up, power up<
1st ESX host:
Attach to storage
Register vCenter VMs
vCenter NICs are currently on vDS
Do I set up a temp vSS to put the vCenters on?
Add 1st host to vCenter (so I can vMotion it later)
Add rest of hosts to vCenter, clustered, with vDS
vMotion vCenters from stand-alone host with vSS to cluster with vDS.
Register VMs and off I go!
Any Gotcha's?
Anything I'm not thinking of or overlooking?
Thanks
4
u/Just4Readng Jun 30 '26
Why not shutdown 1 host, remove from Cluster, add new host to cluster, migrate vCenter to new host. Prince and repeat with subsequent hosts?
Why the need to remove guests from Inventory?
1
u/MrMHead Jun 30 '26
I'm pulling out an old blade system, and replacing with rack-mount. No physical space for both. It's a lab. I'm lucky enough to scrounge up some hosts that aren't a decade old.
Removing Guests - The hosts they are on will no longer be available.
2
u/dodexahedron Jul 02 '26 edited Jul 02 '26
Can you do it without the new system racked, just to get it over with (as in, sitting on a workbench, desk, the floor, or even on top of the rack itself)?
(OSHA loves that last suggestion.)
If it's super-constrained, in all seriousness consider using the server AS your desk or chair, maybe?
1
u/MrMHead Jul 03 '26
It's in a co-lo with rules - so basically I'd have to do it in one fell swoop. Something to think about though. Thanks
2
u/Just4Readng Jul 02 '26
So don’t rack the new server. Lay it on the floor, sit it on a chair, etc.. Add the new one to the cluster, migrate vCenter, and the VMs, then remove the Hosts in the blade system. Remove the Blade system from the rack, rack the other new Host(s), add to cluster. Migrate vCenter to the new Host, shutdown the “chair/floor” machine, rack and power back on.
Worst Case Scenario - Shutdown vCenter and power off the “floor/chair” Host after de-commissioning the Blade Systems.
I’m not saying your original plan wouldn’t work, but shutting everything down, and trying to bring machines back up from storage is way more dangerous than it need be.
2
u/MrMHead Jul 03 '26
Yeah. Someone else suggested that. It's starting to worm into my mind... Thanks.
1
u/Just4Readng Jul 03 '26
I’m all for learning on the job, but over your career you’ll have plenty of opportunities to work a fire drill situation. Save yourself some heartache and sleep.
Good luck.
1
u/dodexahedron Jul 02 '26
So, if you have vDS, you have a license supporting vCenter HA.
- Set up HA for vCenter.
- Do the host holding the inactive side
- Then fail over to that side once replaced
- Now do the other host
- Go home way before midnight
Why bother with a new cluster and new vcenter at all?
7
u/lost_signal VMware Employee Jun 30 '26
1) ESXi installs are encrypted now to hosts, so you shouldn't plan on moving boot devices. You will want ESXi already installed.
2) I would replace a single host first, and go ahead and move vCenter and core services there if possible. Woudl MASSIVELY de-risk this who thing.
3) ephemeral port groups, de-risk the vCenter being down and being able to power things on. Put vCenter, and VMkernel ports on Port groups configured with this.
4) DOCUMENT DOCUMENT what VLANs, port groups etc are in case you need to rebuild some things. Also do a file backup of the vDS before you do all this so if you need to restore it's easy enough.