OS drive usage stats vs clone usage stats

[cwallen19803]

I helped a (non-technical) friend clone his Mac's OS drive to another internal drive, and everything appears to be working normally. We booted to Recovery mode and restored the old drive's partition to the new drive. No real hassles, much easier than I've done in Windows.

He worries about the difference between the disk usage stats between the two drives. He says the total usage is about the same (this over the phone) but that, for instance, the original drive says he has 69 GB of movies where the clone has 33 GB. Ditto for other categories, not matching. The difference appears to be made up in Other.

Is there a way to force the OS to re-evaluate the disk usage for all drives? If it is just categorizing files differently then so what, but it's a hard argument for him to accept. I told him he should easily be able to find a missing video file, assuming it is missing, simply because 1/2 of them aren't (possibly) there.

From my perspective, I don't see how a cloning operation that took 2 hrs could have not done the job completely. We know the machine is booting from the new drive. I had him rename the partition and select it as the Startup Disk.

I've recommended that he download Disk Inventory X and compare it's analysis of both drives. I am familiar with it's Windows cousin, Windirstat.

Much ado about nothing?

 

[pm-r]

Much ado about nothing?

Probably…

As you said, he can use one of the utilities like Disk Inventory X and/or GrandPerspective, or if he wants to get really fussy he could use Find Any File and do a find on separate file types (.extension) and compare the results:
http://apps.tempel.org/FindAnyFile/

BTW: Where are the results for the "difference between the disk usage stats between the two drives coming from???

That remark "the original drive says he has 69 GB of movies where the clone has 33 GB" sure does seem rather an excessive difference.




- Patrick
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[MacInWin]

The About This Mac assessment of drives is notoriously inaccurate. It is indeed, "much ado about nothing." As Patrick said, if he wants details he can use a third party tool, but as long as it's working and his files are there, tell him not to worry about the discrepancy because the ATM process is so inaccurate.

 

[pm-r]

…tell him not to worry about the discrepancy because the ATM process is so inaccurate.

I'll add that the discrepancy is so vague and inaccurate that's it's an embarrassment that Apple even includes it. It only barely works as a general guideline and only for the boot volume unless they changed or improved that.

At least the OS X Get Info window still works for files and folders and their sizes, and another way they could check things between the clone and original.




- Patrick
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[cwallen19803]

Probably…

As you said, he can use one of the utilities like Disk Inventory X and/or GrandPerspective, or if he wants to get really fussy he could use Find Any File and do a find on separate file types (.extension) and compare the results:
http://apps.tempel.org/FindAnyFile/

BTW: Where are the results for the "difference between the disk usage stats between the two drives coming from???

That remark "the original drive says he has 69 GB of movies where the clone has 33 GB" sure does seem rather an excessive difference.




- Patrick
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The results I described come from the "About ...", System, Storage

As far as 69 vs 33, I suspect that he has a corresponding difference in the other direction in the Other category. Personally I think it is nothing. The chances that the clone would have copied enough of the OS to produce a functioning system and yet omit half his video files vs. half of all files, well I just don't buy it. We cloned the original drive on to a USB drive also and the category numbers don't match either drive, so either it did it wrong twice but in a different way or the category counts are just wrong. I'm going to have to use another tool or a simple folder by folder file and byte count.

 

[Slydude]

There have been some good suggestions so far. Rather than searching for files by extension I'd probably use one of the file / folder synchronization utilities to compare the two drives and see what the differences are. There are a number of these apps in the App Store some free and some paid. Many of these programs can be configured to show you any files that are in different between these two drives.

A couple of other factors may affect the drive space numbers perhaps others can comment on the extent that these things come into play in this situation:
1. When a drive is cloned not all files are copied IIRC. Some files are not copied because they are recreated when the drive is booted from the clone. The files I'm thinking of are usually relatively small though and would not account for the differences seen here.
2. There might be a difference in the minimum size "blocks" on each drive. Again I'm not sure if it is as much of an issue as it used to be.

 

[bobtomay]

About This Mac - Storage is a piece of trash app that is good for N O T H I N G except to see how much used and free space you have on the drive.
It is highly unlikely you will ever get Storage to present you with the same info on 2 separate drives.

Currently, on my primary drive Storage indicates that 244 GB out of 265 GB are Apps and 0 GB of Other.
Meanwhile, on my clone, About this Mac - Storage claims it has 242 GB of Other and 0 GB of Apps.

It has always been and still is a W O R T H L E S S piece of trash for looking at what types of files are taking up space on a drive.

Tell your friend to get a real app like DiskInventoryX you've already recommended (I'll throw What Size into the ring as my favorite utility in this category).
Also tell him/her as long as they're using About This Mac to see what sorts of files are on the drive, you can't assist him any further.

 

[cwallen19803]

Thanks all. bobtomay's example will simply freak him out.

 

[pm-r]

Thanks all. bobtomay's example will simply freak him out.

Well here's another example to show him how useless it is on my iMac with four OS partitions, and they'll have to agree that it's pretty useless for anything other then providing general size information — unless he is some sort of Apple Fanboy!! And if that's the case, maybe he should call Apple and discuss the situation with them.





- Patrick
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