Reinstall ESXi on a host in an existing cluster

[spoynter]

I have cluster running ESXi version 6.7 u3.  I need to reinstall ESXi on one of the hosts.  All VM storage is on a SAN and no vSAN is being used.  Only storage on a host server is the OS install.  Would the following steps be the recommended behavior for performing the reinstall:

1. Backup ESXi configuration using this article (https://kb.vmware.com/s/article/2042141)
2. Put host in maintenance mode.
3. Disconnect host from cluster.
4. Wipe and reinstall the same version of ESXi as before.
5. Restore ESXi configuration using the same article referenced in item 1.
6. Re-connect host to cluster.
7. Exit maintenance mode.

Does anyone see any issues with this?  Thanks...

[spoynter]

Just to add in regards to step 3... should I be disconnecting for removing the server from the cluster via the "Remove from Inventory" option?

[ObjectifDubai · Accepted solution]

Hi,

-->  To already answer your last question, no you must not delete the server you are installing from the inventory

--> I don't know what VMWare license you have, but if it's a "vSphere Enterprise Plus" license, I would advise you to backup your ESXI configuration by creating a "Host Profile", otherwise effectively I I've never done it but saving its configuration is a good idea, it will save you from having to configure your esxi manually.

--> For me step 3 is not necessary. After placing your server in "Maintenance Mode" connect to your server's console (via iLO, iDRAC, ....), stop the server and start the server on the installation iso.

--> In Step 4, there is no need to delete the data, this step will be done automatically during installation. When installing the OS I also recommend the option "InstallESXI, overwrite VMFS datastore"

--> Between step 4 and 5 (Restoration or Host Profile application), you must connect to the ESXI interface and configure at least the Management IP address there.
If you have never installed an ESXI, I advise you to connect to the console of your server (via iLO, iDRAC, ...) and note the configuration there

[alantz]

I like to export host customizations under host profile if you use host profiles. This creates a CSV that will have some good info like IQN for iSCSI and your vmKernel IP addresses that you could manually re-enter later if the export/import of your settings didn't work for some reason.

--Alan--

[spoynter]

Thanks for the reply.  Out of curiosity, why do you say I shouldn't remove from the inventory?  I actually ended up removing it after backing up the configuration.  I then reinstalled, configured the management interface, restored the configuration, and re-added to the cluster.  Everything seems to be working fine for the moment.  The only options I had when installing were either upgrade or install.  The install option automatically repartitions before the install.  There was nothing to keep here so I was okay with that option.

[ObjectifDubai]

Hi,
Unless you want to change the name of your ESXI, it is useless to delete it from the inventory.

I will give you an example that comes to mind, if for example there are DRS rules with your ESXI, deleting the ESXI from the inventory will alter your rules and force you to modify them manually again when inserting your ESXI.

[spoynter]

Understood.  I checked VM/Host rules for the host before removing it so there were no issues there.  Whether to remove from inventory or just disconnect was the only thing I was unsure about, and I couldn't find any clear documentation about what to do there.  I appreciate the clarification.  Thanks...

[ObjectifDubai]

Hi,

At the vCenter level if you disconnect your ESXI I think you also keep the history of events. If you delete the ESXi from the inventory you lose this history because it is a new object that appears. I think there are other subtleties that I don't have in mind.

[spoynter]

I'm okay with a clean start in this case.   I have six identical servers at the same ESXi patch level.  Installed some patches about a week ago.  After about 4 to 5 days this one randomly started to experience hard freezes every day or so with no accompanying PSODs.  Hardware diagnostics all passed, so as a latch ditch effort I figured I would just wipe the machine and reinstall.  All the other servers have been stable.  So far since the reinstall things have been good.  I'm going to give it another few days before declaring victory though.

[ObjectifDubai]

Well I hope this solves your problems. Good luck 😉