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mamelasFlag for Greece

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Reinstalling ESXi OS on top of existing installation

Dear Sirs,

We are facing performance issues in one of our ESXi 6.5 U1 Hosts.

I was told by VMware Support to perform a re-installation of ESXi OS on top
of the existing ESXi installation and monitor the Host's behavior.

The installation Windows of ESXi provide us 3 options:
- "Upgrade-preserve VMFS "
- "Install-preserve VMFS"
- "Install-overwrite VMFS"

In order to perform a "Clean" installation, I would select the option "Install-overwrite VMFS"
Host's VMFS is empty since we are using Shared Storage to Host the VMs.

My concern is, If the VMFS is overwritten will it lose the Network configuration, IP, and any other configuration related to the vCenter?
Or all this information is saved into vCenter?
Will the Host lose the connection to vCenter and HA configuration?

Thank you in advance,
Mamelas
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Richard Faulkner
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You will have to put the information in to the host when you are doing the install. It will ask for IP, Mask, Gateway, etc. Once it is up, you will have to add it back manually into VCenter. Additionally, if you are not using DVswitches or host profiles you will have to setup all your network connections again, rescan the scsi busses etc. 
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Seth Simmons
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VMware Support said re-install?

Are you paying for support???

#WTF
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ASKER

Dear Andrew,

Thank you for your participation.

Yes, I am paying for Production Support...

The actual issue was that the VMs running under a specific ESXi Host, for some reason, were automatically vMotioned to the second Host.

I, therefore, created a ticket to VMware for further investigation. Unfortunately, the logs were overwritten and as result, the assigned Engineer could not retrieve the logs for further investigation (I opened the ticket more than 20days after the issue has happened).
During the troubleshooting session, we both noticed that the Host is taking too much time to load the Web Gui (although no VMs were running) and I was instructed to try to reload/reinstall on top of the OS of ESXi, move some VMs to this Host and then Monitor Host's behavior.

That was the reason why I created the subject question.

I finally decided to go to the safe side and instead of Installation with Overwrite, I performed an Upgrade (by using the same ESXi OS Version ISO file).

Now the ESXi is running 4VMs, it seems that has not performance issues, and I am monitoring his condition to see if the vMontion will be triggered again.

But why you are against re-installation?
I find it appalling and sloppy that VMware support,  have basically just said turn it off and on again!

or re-install in your case, rather than diagnosing!
Avatar of mamelas

ASKER

Yes I get your point.

The Engineer could not retrieve the logs because the issue has happened days before opening the ticket to VMware Support and the logs were overwritten.

That said, he recommended to reinstall the OS and Monitor the ESXi and if the issue is repeated I should re-open the ticket in order the required logs to be available this time...
Yes, I appreciate the logs.... but this does not make any sense


"During the troubleshooting session, we both noticed that the Host is taking too much time to load the Web Gui (although no VMs were running) and I was instructed to try to reload/reinstall on top of the OS of ESXi, move some VMs to this Host and then Monitor Host's behavior."

The Engineer should have been able to diagnose WHY, otherwise no point in having any VMware Support contract might as well use EE for your VMware Support and save MONEY!

That said, he recommended to reinstall the OS and Monitor the ESXi and if the issue is repeated I should re-open the ticket in order the required logs to be available this time...

I would recommend setting up a Syslog server, to ship all the logs off the server, if you have not already done so.