Time Machine fails backup: "an error occurred while copying files"

[Jethro!]

After the old one got full, I recently got a new external drive for backups. But backups on the new drive repeatedly failed, so I got a replacement enclosure and drive, but the same problem persists. Backups randomly fail, and the only info TM gives me is...

"an error occurred while copying files"

Not very helpful, TM. The external drive then also becomes severely corrupted, fixable only by reformatting. Then back to step 1. I've also used Disk Warrior on my main iMac drive to ensure it is in good shape, but still have the same problem.

Anyone know what's going on and how to fix it?

OS 10.13.6 iMac Late 2013

 

[Fishrrman]

You didn't ask this... but...
Give a try to either CarbonCopyCloner or SuperDuper.
Both are free to download and use for 30 days.
SuperDuper works free forever (if you do a complete cloned backup each time).

If you don't like the results you see, just erase the drive and start over.

 

[Jethro!]

I have both CCC and SuperDuper, but TM is just usually more convenient. Wondering why TM is repeatedly failing.

 

[chown33]

Maybe it's the cable.

Also, what's the exact model of the new drive, and what format is it?

 

[Jethro!]

It's the same cable that worked fine with the previous drive. Nothing disturbs it. I'll try another one.
It's a new OWC enclosure with a Toshiba HD.
The TM failures always happen when I've been away from the machine for some hours letting it run. The screen is dimmed, but not asleep.

 

[Jethro!]

Maybe it's the cable.

Guess what? I tried a new cable and it worked this time. Guess that was it? Who knew!
Thank you.