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chuckm1020

macrumors regular
Original poster
Aug 27, 2009
149
28
So I just formatted one of my 1TB hard drives so i can use time machine with it. I just did a quick erase because it seems pointless to wait forever to wright zeros over it. It says that this is a little over 600MB's used on the hard drive still. Ive done the format 3 times and after every format this number still stays the same. Any idea guys? Thanks
 
Is the drive partitioned?

If you're wondering what "Other" category in the Lion storage tab is about, this may help explain:
For space issues not explained by the above, there are a few things you can try, some of which may or may not apply:
  • Begin by restarting your computer as a first step. This sometimes resolves issues.
  • For Time Machine users on notebooks running Lion, space may being consumed by Time Machine local snapshots, which can be disabled.
    OS X Lion: About Time Machine's "local snapshots" on portable Macs
  • Search with Finder to see if the space is being consumed by a very large file or several large files. Adjust the 50GB in the illustration to whatever size you deem appropriate.
    attachment.php
  • Use OmniDiskSweeper, JDisk Report, Disk Inventory X or GrandPerspective to see how space is being used on your drive. Some of these apps may show more detail than others, so try several.
 
Here we go. Looks to be the same 209.7MB, its the very last HD
 

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I have the same issue as the OP.

I installed a brand new 4 TB drive (never used before), formatted it many times, and it still is saying 1.11 GB of space is used. I also 'Erased Free Space' on the drive and it still is listing 1.11 GB used.

What is even more strange is that Disk Utility says the drive's Capacity is: 4 TB, Available: 4 TB, and Used: 1.11GB. :confused:

I also have iStatus Menu and it says the drive is 3.63 TB (which should be the correct available space) but it also says 1.11 GB of used space.

I've ran many hard drive Apps to try and find the missing space but nothing was found. The Apps find no data on the hard drive.

Any ideas?
 
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Are you forgetting that every file system has overhead, and that 1 GB in 4 TBs isn't that much?

For perspective, it is 1.11 / 4000 or .028% of the total available space.

That's what I was thinking it might be; I guess I was just a little shocked that it was such a large amount.

Any idea why Disk Utility is reporting 4 TB for both Capacity and Available space even though 1.11 GB is reserved for overhead?
 
That's what I was thinking it might be; I guess I was just a little shocked that it was such a large amount.

Any idea why Disk Utility is reporting 4 TB for both Capacity and Available space even though 1.11 GB is reserved for overhead?

The bigger the file system the bigger the overhead. More potential inodes, more data blocks to track. I don't consider the fs overhead to be significant.

Disk utility only reports down to 10s of gigabytes on terabyte + volumes so with just 1 gigabyte in use it is below the reporting threshold.
 
Had exactly the same on my 2012 Mac Mini's 1TB HDD after formatting – I had moved boot/apps to a new separate Samsung 840 Pro 256GB SSD inside it (and yes, the Recovery HD was on the SSD, so it wasn't that).

The HDD still showed ~650MB used after formatting.

I thought it was likely the EFI (~200MB) and other overhead inode info (? MB), but still sounded a lot to me.

Hence next day went and spoke to local Apple Store's (non) Genius, who told me it was normal and to not worry about it.
To be honest, dunno why bothered, because as expected he knew fu*k all! Hence why I say NON-genius, as I basically walked him through checking hidden files (I'd checked already!) and pointing out the EFI figure to him (again, checked already!), etc. – and i'm not even that techie at all. :-|

Real idiots most of the people Apple are hiring these days as 'Genius' staff. Unknowledgeable, disinterested, 'you're 8 mins are done and you can now piss-off' –type attitude!

AppleCare is really worth the hardware ONLY (if you can be bothered).
 
Had exactly the same on my 2012 Mac Mini's 1TB HDD after formatting – I had moved boot/apps to a new separate Samsung 840 Pro 256GB SSD inside it (and yes, the Recovery HD was on the SSD, so it wasn't that).

The HDD still showed ~650MB used after formatting.

I thought it was likely the EFI (~200MB) and other overhead inode info (? MB), but still sounded a lot to me.

Hence next day went and spoke to local Apple Store's (non) Genius, who told me it was normal and to not worry about it.
To be honest, dunno why bothered, because as expected he knew fu*k all! Hence why I say NON-genius, as I basically walked him through checking hidden files (I'd checked already!) and pointing out the EFI figure to him (again, checked already!), etc. – and i'm not even that techie at all. :-|

Real idiots most of the people Apple are hiring these days as 'Genius' staff. Unknowledgeable, disinterested, 'you're 8 mins are done and you can now piss-off' –type attitude!

AppleCare is really worth the hardware ONLY (if you can be bothered).

I'm also having the same problem as you. After googling for hours, I still can't find a solution to remove that space. Although 600mb+ is not really a big deal, I am still quite disturbed about it. :(
 
HFS+ preallocates space for the invisible “catalog file” and other metadata to prevent fragmentation.

The two main reasons are:
1. File system repair tools can find the file system metadata more easily, which increases the chances for a successful file system repair.
2. Performance. The OS caches the file system metadata in the RAM. On systems with large volumes and many files/folders, the system caches only some parts of the metadata, which means that the OS must read some file system metadata from a potentially slow HDD. Non-fragmented metadata increases the read performance on HDDs.

----------

...even though 1.11 GB is reserved for overhead?
It is no overhead. It is part of the file system.
 
Taken from an article from Popular Mechanics (http://www.popularmechanics.com/technology/how-to/4206535):

Your hard drive is advertised as having a 60GB capacity, but your computer shows only 55.8GB. What gives? The discrepancy is the result of having two methods of measuring memory. Computers are binary, or "base two," mathematical systems, and in a binary world a kilobyte is 1024 bytes (2 to the 10th power). When computers were new, the geekerati referred to this as a "kilo." Noncomputer folks, however, understood kilo to mean thousand, and thought that 1000 bytes should equal a kilobyte. So, two different measurements of hard drive space were born. In 1998, the International Electrotechnical Commission (IEC) weighed in, defining 1 "gigabyte" as 1 billion bytes. Hard disk manufacturers agree, marketing their products using the rounder decimal value instead of the binary system. So, your drive is labeled as decimal ("giga") and your PC reads binary (IEC's term, "gibi"). Either way, you're getting the same bunch of bytes.



So take the "math" plus the additional overhead the OS uses for cataloging/metadata/etc, there's your answer; that is not user editable space... that's just the way it is...

--rob
 
Taken from an article from Popular Mechanics (http://www.popularmechanics.com/technology/how-to/4206535):

Your hard drive is advertised as having a 60GB capacity, but your computer shows only 55.8GB. What gives? The discrepancy is the result of having two methods of measuring memory. Computers are binary, or "base two," mathematical systems, and in a binary world a kilobyte is 1024 bytes (2 to the 10th power). When computers were new, the geekerati referred to this as a "kilo." Noncomputer folks, however, understood kilo to mean thousand, and thought that 1000 bytes should equal a kilobyte. So, two different measurements of hard drive space were born. In 1998, the International Electrotechnical Commission (IEC) weighed in, defining 1 "gigabyte" as 1 billion bytes. Hard disk manufacturers agree, marketing their products using the rounder decimal value instead of the binary system. So, your drive is labeled as decimal ("giga") and your PC reads binary (IEC's term, "gibi"). Either way, you're getting the same bunch of bytes.



So take the "math" plus the additional overhead the OS uses for cataloging/metadata/etc, there's your answer; that is not user editable space... that's just the way it is...

--rob

Erm NO, this is nothing to do with base 2 vs base 10. If you bothered to read the actual posts, the figures were all taken from what the Mac was showing in Disk Utility, so your point is completely irrelevant.

It is to do with filesystem overhead, as others have previously explained already.
 
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