External HDD(s) misreporting free space

Mercenary Keyboard Warrior · 7 Feb 2011 at 16:37

Been sorting my data out which has mean't a load of copying around. This is via external caddies.

I noticed a disk seemed to have too little free space when considering what I had on it. I checked the sizes of the files and they came to 187GB, the disk is showing as 931Gb (formatted in win), used 310Gb, free 621Gb.

I have checked via properties and run a disk clean up incase there were any files that had been deleted but not properly flagged to the disk. This didn't throw anything up. So I have quite a bit of missing space.

I then checked a few others and I have the same issue on another disk, again the used space is higher than the actual space ofthe files, this tiem by 25GB.

One is a fixed external drive unit the other is a removable caddy so completely diff hardware.

So whats causing this issue, could it possibly be renaming files? The files are large and have been named and renamed a few times in some cases with stuff like "backup" added or a date etc.

Chkdsk is reporting more files than there are physically on the disk so it looks like some kind of data multiplication.

Oh btw these are NTFS formatted.

rpstewart · 7 Feb 2011 at 17:36

What are you using to check the space?

Do you have system restore enabled on those drives?

Mercenary Keyboard Warrior · 7 Feb 2011 at 17:39

Ok update. I moved the files and folders one by one until the disk was empty. This disk with teh 25GB diff continued to show 25Gb in use. The disk was empty. I check for system and hidden files and folders and there wasn't any as I expected.

I formatted the disk and the only used space is now 133MB.

Can't do the same to the larger disk atm but will do later.

So any ideas what could be doing this? Could it be the files tables are growing but never reducing in size maybe since they are external disks and not internal.

Mercenary Keyboard Warrior · 7 Feb 2011 at 17:42

Checked space used by selecting all the files and using properties to see the size used. This agrees with the sizes from the source disks on host system.

Where can I check on system restore, don't think its set but then I cannot swear 100%. Although these have been plugged to a number of computers its possible its been on for one of them, but I assumed any restore/backup etc type options would not apply to removable storage.

Mercenary Keyboard Warrior · 7 Feb 2011 at 17:48

Ok found and checked, only system protection is running on C

rpstewart · 7 Feb 2011 at 17:50

Something like Treesize Free should give you an idea what is using the space better than just checking each directory in turn.

Mercenary Keyboard Warrior · 7 Feb 2011 at 18:26

Forgot to say, tried that was well, it agrees with the 187Gb (it shows 187.6GB) and the folders its in.

Its something to do with the file system I am sure of it, just can't work out what or why.