SOLVED Exact folder contents in bytes

[James Adrian]

I have two external drives for backup that I keep identical, if I can. One has 90.95 GB free, the other has 90.86 GB free. According to the folder and file byte counts reported by the system, every count is the same, but only to a certain resolution; therefore, I cannot find which file or folder name is not identical in both drives.

Is there a way to get the byte size of a folder accurate to the byte regardless of how large the folder is?

Thank you for your help.

Jim Adrian

 

[Cory Cooper]

Hello,

-Are the two drives the same brand/model?
-What type of backup - Time Machine, CCC, SuperDuper!, etc.?

C

 

[James Adrian]

Cory,

In this case, they are two identical flash drives bought from Amazon a few days ago. The brand name is Lexar.

Jim Adrian

 

[Cory Cooper]

OK, thanks.

It could simply be a hidden file, like the Spotlight index.

How are you making the backups to them - dragging files in Finder, Time Machine, third-party app like Carbon Copy Cloner/SuperDuper!/Sync Folders Pro/etc.?

C

 

[James Adrian]

Cory,

I don't use time machine or any third-party software. I write a text file or an html file in TextEdit, and save it to both flash drives. Older files are copied to the flash drives from folders on the desktop or folders inside folders on the desktop.

Isn't this about the rounding error when it simply says a file is 2 MG? Isn't it the case that if one file is 12 bytes bigger than the other that it will not report the difference?

Jim Adrian

 

[James Adrian]

It finally occurred to be to do a test. I added ten bytes to a 6KB folder and the operating system reported the size as 6KB.

How do I get a readout that is accurate to the byte? Is this impossible?

Thank you for your help.


Jim Adrian

 

[Cory Cooper]

OK, understood.

Yes, it could be due to the rounding of file sizes, due to the allocation block size differences of HDD/SSD/flash storage, as well as the partition scheme and format type. If the number of files is equal on the two flash drives, then I would feel pretty good that the disks are identical in that way.

You could use an application like OmniDiskSweeper or WhatSize to view the contents of the two flash drives. You may be able to narrow down any significant differences.

C

 

[James Adrian]

Cory,

Thank you for these links. I didn't find that the exact but size of files and folders were claimed as a feature for either of them but I found that the os has a way of doing it. I found this online:

How to Determine the Size of a File or Folder

Steps on how to determine the size of a drive, file, files, or folder on your computer.

www.computerhope.com

Locate the file or folder whose size you would like to view.
Click once on the file or folder.
Press Command + I on your keyboard.
A window opens and shows the size of the file or folder.

It works!


Jim Adrian

 

[Cory Cooper]

Yes, the Get Info command is very helpful, but won't drill down to see the actual differences. I am glad you found some form of solution/answer.

Be well,

C

 

[James Adrian]

Cory,

The complete solution requires making hidden files visible. These greyed-out files contain regular files that can be moved. The two Lexar flash drives now show the same number of gigabytes free.

I think this thread can be called SOLVED. Is that right?

Jim Adrian

 

[James Adrian]

What is the procedure for getting a thread declared solved?

Jim Adrian

 

[Cory Cooper]

Hello,

Yes, it can be marked as solved if the resolution you came to is satisfactory. Just click the Mark as Solved button at the top right of the thread. Normally, it is best to keep the hidden files hidden, as some of them in certain locations are needed by OS X/macOS. Others are things like the Spotlight index, folder view options, trash, etc.

Be well,

C