I have just purchased a Seagate external drive I need to reformat for use with Time Machine.
My understanding is I launch disk utility, select the drive, click erase and choose "Mac OS Extended (Journaled)"
My question is --
When I go into Disk Utility, I see two different possible items and am unclear which to run the erase protocol on. Or should I do both? See screen grabs below.
iMac, macOS Sierra (10.12.6)
Erase the uppermost, unindented icon (the entire drive). This will also erase any preinstalled software and drivers, which is what you want as they are unnecessary with Mac OS and can actually slow the drive. The format should be Mac OS Extended, partition scheme GUID.
Macjack is spot on - I just wanted to your FYI:
If you'll look at your first screen shot, you can see that it is formatted for Windows (Master Boot Record) as most external drives are. Getting rid of their superfluous software is good - it serves no purpose.
(duplicate)
how to format external hard drive for time machine
