filesystems - php disk_total_space() minus disk_free_space() does not equal occupied space -

I wanted to see the available space on storage, where I am storing user attachments. I went along and the result is:

Free space: 5.47 GB total space: 5.86 GB

then occupied place = 0.39 GB .

I have captured the files 18.34 GB in the hidden amount to capture their size through files. (Maximum file size is 4MB, so note note about 2 GB applies)

Such:

Total space - Free space ! = Acquired Location

Why?

The file system is on HP-UX. I measured all the values ​​using the same account - I run all the commands from php script by executing the script with an internet script.

I also checked the functions in Windows, the results were OK.

I went through some other questions related to the function (,,,,), but got no answer.

Depends on the OS and the filesystem used depends on the directory that you Function calls. The reason for this is that Linux keeps several drives in one big tree. You can not just call disk_total_space ('/') , because it only gives you the size of the root partition. Try the disk_total_space ($ attachmentFolder); .