Should I erase internal HD drive now that I'm using an external SSD for the boot drive?

[Macky-Mac]

I have a late 2013 21.5" iMac that I now am using an external SSD as the boot drive. I have Mojave installed.

I'm wondering if I should delete the system folder on the old ailing internal HD?

I have all my files backed up on external drives, so perhaps I should just erase and reformat the old internal drive? It may have started to fail anyway, so I'm not planning on storing anything important on it.

 

[rpmurray]

Sounds prudent to do so. You may want to also then set the Energy Saver option to "put hard disks to sleep when possible" to keep it from spinning and wasting energy.

 

[Fishrrman]

What you could do:

Erase the internal drive to clean it off,
then
Use either CarbonCopyCloner or SuperDuper to create a bootable cloned backup of your external SSD onto the INTERNAL drive.

Why do this?
Because you always, always, ALWAYS want to have a "second bootable drive" within VERY close reach.
What would you do if your external SSD fails?
How would you get booted?
(I've had a couple of SSD's just "go dark" on me, never to be seen again)

Both CCC and SD are FREE to download and use for 30 days.
My suggestion will cost you nothing.
(If you've never used either of these apps, I assure you that you will be impressed by the results you get)

 

[Macky-Mac]

What you could do:

Erase the internal drive to clean it off,
then
Use either CarbonCopyCloner or SuperDuper to create a bootable cloned backup of your external SSD onto the INTERNAL drive.

Why do this?
Because you always, always, ALWAYS want to have a "second bootable drive" within VERY close reach.
What would you do if your external SSD fails?
How would you get booted?
(I've had a couple of SSD's just "go dark" on me, never to be seen again)

Both CCC and SD are FREE to download and use for 30 days.
My suggestion will cost you nothing.
(If you've never used either of these apps, I assure you that you will be impressed by the results you get)

I like your suggestion.

I'll erase the internal HD, but since I don't have any confidence in its ongoing condition, I'm not going to rely on it.

As my "second bootable drive" strategy for the moment, I do have a another external SSD with a fresh install of Mojave on it .........it's unused but sitting nearby; "just in case"

Maybe I'll make a full clone of the current external SSD onto the standby SSD.