ZenON,
I'd like to also add some suggestions, first make sure you have two policies, a No-Scrub policy and a Scrub policy created in UCSM. Make sure you apply this No-Scrub policy to the appropriate section for your service profiles. If they are bound to an updating template, assign it there and if they are individually created profiles, you may need to edit each one individually. Set all scrub options to no. The policy with the Scrub option enabled should only be used for a scenario when you want to wipe that boot OS off the SD media to re-purpose the blade for another function or want to re-install the image for a fresh start.
If you currently have ESXi installed and already configured I would take a backup before you make any changes that you are not sure are disruptive. The backup of your VMware configuration will allow you to avoid rebuilding the entire ESXi host each time an issue occurs. See https://kb.vmware.com/s/article/2042141 for reverence on how to backup an ESXi host. With VMware Enterprise Plus you can also make host profiles in vCenter to the same effect, but the ESXi backup will work on any version regardless of vCenter integration.
