I Turn Off Time Machine Before Smart Update--Necessary or Not?
 

I always do a test boot from my clone after I do a smart update just to check. It began to occur to me that something weird might happen if during the test boot from the clone, that Time Machine became active and started doing a backup. I'm not sure how that would work out. So I started opening Time Machine preferences and turning it off before I do a smart update, then do the smart update, then do my test boot from clone, then reboot to my internal HD and then turn Time Machine back on. I'm not sure if this is overkill or not. Any ideas? Thanks.

Not really necessary: you could always disconnect the Time Machine volume to ensure that it doesn't back up when started up from the copy...

Thank you very much.

Kind of hard to do if the TM volume happens to be on an internal drive (e.g. in a Mac Pro). :)

I consistently get a "can't find valid TM volume" error (something like that), or TM isn't yet scheduled to run, right after restarting my Mac mini with an external drive connected that contains a TM volume. Always gives me enough time to manually unmount it if I don't want it online.