Copying large volumes of data in Finder - destined to fail?

[cosmichobo]

G'day,

I've just draged 700GB worth of files from one drive to another on my Mac Pro5,1 (Sierra; external Firewire to internal). It says it is going to take 3 hours.

In retrospect, from my experience, these types of copy jobs rarely go well. Typically at some point they tend to fail part way through, leaving you with uncertainty about what has / has not copied successfully. (Did a file part-copy, is anything trust-worthy).

This could be from internal to external, or really any type of drive to drive copying, based on experience across OS X since 10.3. (Though - perhaps not a lot of experience with Sierra...)

Am I just a pessimist, or do others find this too?

Cheers

cosmic

 

[cosmichobo]

And on this occasion... I have to eat my words.

Copied successfully.

To be continued...

--
Biting my tongue again... am currently copying about 3.5TB of data across to a new drive. I did break it up into a few chunks, a couple 500GB, and last one I'm now leaving overnight of 2.5TB. So far - all good. Will see in the morning what happens...

 

[chown33]

If I have huge amounts of copying across drives, I usually use Carbon Copy Cloner, because it continues when it gets an error, and has more informative error reporting.

It's been quite a while since I've seen any errors, so I don't even remember what it looks like.

Oh, and I also do the "copy in parts".

 

[MacCheetah3]

I haven't had many copy failures. From what I recall, most were due to permission conflicts, restrictions, etc.

I think, your attitude is skewed, though not unreasonably as copying in (macOS) Finder and (Windows) Explorer is a poorly implemented transaction. It's not an all or nothing but is also not a seamless resume. So, for large, combination copies, a failure and reattempt is very tedious and thus typically memorable.

 

[cosmichobo]

Yes - it's probably just the memory that - this job was half way through a 5 hour copy, and failed!!! Rather than it being a "big" issue.

The job in my post above still has 22min to go - but no issues encountered.

I think my irritation comes from the fact that when these failures occur, the Finder doesn't offer to ignore the problem file and keep going. At least then - you know where you stand (assuming nothing else fails - but again, it could give a list of problems...).

 

[Fishrrman]

It often works better when copying "large amounts" of data...
... to copy it "in smaller portions" instead of all-at-once.

As mentioned above, CarbonCopyCloner CAN do high-volume copies, because it won't quit (as will the finder) if it encounters one or more "files with problems". It will just "take note" of them, then "go around" them and keep copying the good files until the job is done.

 

[cosmichobo]

I'm now copying about 3TB of data back to the external firewire - a 14 hour job - half way through.

Maybe Sierra does a better job than previous iterations of OS X. The reason it was fresh in my mind, was that at Xmas I was at my parents, dealing with their 2008 iMac running Mavericks - and it was terrible at copying large volumes of data... which reminded me of all the issues I've had in the past with this.

But so far, Sierra has handled everything I've thrown at it.

 

[MacCheetah3]

I think my irritation comes from the fact that when these failures occur, the Finder doesn't offer to ignore the problem file and keep going. At least then - you know where you stand (assuming nothing else fails - but again, it could give a list of problems...).

I understand.

Not ideal, but at a minimum reverse the entire transaction. Finder only gives a vague report on progress and integrity isn’t 100% guaranteed — as you mentioned. Therefore, most users end up recopying the entire bunch anyway, or at least attempting to after isolating the single mentioned problematic file.