If I am using the ArcGIS Enterprise Patching tool to search and install patches, do I need to shut down portal / data store services prior to installing the patches?
In a live environment it is best to have an outage to avoid users making configuration changes during the patch installation. Data Store is only accessed through Portal/ArcGIS Server, so you don't need to shut that service down. You can put Portal and ArcGIS Server into read only mode to enforce an outage.
I would also ensure that there are recent snapshots of the impacted machines before running the patch installation process.
I agree with Mark's comments completely, but I would go one step further and say don't use the tool to patch production. I find the tool convenient for seeing if a machine is missing a patch, and even downloading the patch, but trying to apply multiple patches has never worked for us. We have had instances where the tool downloads the wrong version of a patch, so of course the patch won't install. We have also had instances where it shows patches are missing that aren't applicable to the machine.
The tool is a good idea but not fully baked, and I would not trust patching my production machines with it.
When you install a patch, the patch installation shuts down the component you're installing the patch for anyway. If you shut down the service yourself, the installation will start it after.
There's no way to prevent downtime for a non-HA deployment when installing patches.
If you shut down the service yourself, the installation will start it after.
We actually find that behavior of the patches annoying, i.e, the auto-restart of the Windows service after applying. Fortunately, it is easy to work around.
Thanks everyone for your contributions. We have found a flow on consequence in that the indexing got out of sync after the patching, so need to re-index the portal environment.