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Veltliner · Feb 10, 2009, 11:34 PM

How can this be?

I had 35 Gb available space on my hard drive, erased a few hundred mb, and ended up with 34,71 Gb available.

Does this mean my hard drive is somehow messed up? I know there's no defragment function for the mac, but what kind of hard drive care could I perform?

Veltliner · Feb 10, 2009, 11:40 PM

What I did was erasing images that were part of an old Lightroom database - but I did it using Bridge CS3.

Shouldn't lead to problems, though. Or what do you think?

PS: the space showed up after a restart. Puzzles me. Usually the "space available" updates right away.

besson3c · Feb 10, 2009, 11:55 PM

HOw much memory do you have? Sounds like you were using virtual memory.

Veltliner · Feb 11, 2009, 12:24 AM

I have 3Gb RAM.

I had two images loaded in Photoshop, but each wasn't larger than 300mb.

Now, the "available disc space is down again to 34,7. As if my computer wasn't really sure how much there was, so it's once this number, once the other.

Could the Lightroom database play jokes with the system? I mean I didn't erase those files using Lightroom (which I no longer run). I just used Bridge CS3.

Veltliner · Feb 11, 2009, 12:30 AM

Maybe Bridge CS 3's cache takes up virtual memory...

Art Vandelay · Feb 11, 2009, 12:43 AM

Bridge has a scratch space, like many other Adobe apps.

MacNNUK · Feb 11, 2009, 01:32 AM

Did you empty trash ?

I have found with erasing image files that the folder sometimes does not reflect the new contents size, I open new folder transfer contents there, copy and paste rename with a space at the end, and erase old folder.

(The space means you can have both in same location, until original erased.)

Thorzdad · Feb 11, 2009, 03:50 PM

Actually, I've noticed the very same thing on my Mac from day one. Some odd glitch that occasionally reports less available disc space after a deletion (including Trash emptying). If you log-out, then back in, it will read correctly, though.

Veltliner · Feb 12, 2009, 03:09 AM

Originally Posted by Thorzdad

Actually, I've noticed the very same thing on my Mac from day one. Some odd glitch that occasionally reports less available disc space after a deletion (including Trash emptying). If you log-out, then back in, it will read correctly, though.

I had the experience that after the restart the cleared storage showed up - and then disappeared again. Exactly the same amount.

Veltliner · Feb 12, 2009, 03:10 AM

Originally Posted by MacNNUK

I have found with erasing image files that the folder sometimes does not reflect the new contents size, I open new folder transfer contents there, copy and paste rename with a space at the end, and erase old folder.

That sounds interesting. Haven't noticed it yet, though.

CharlesS · Feb 12, 2009, 03:14 AM

Originally Posted by Veltliner

I had the experience that after the restart the cleared storage showed up - and then disappeared again. Exactly the same amount.

That's probably just your swap file, which will grow and shrink as needed. Because of the swap file, I usually consider the amount of free space to have a margin of error of about 6 GB or so. This is also why I find these "hints" some people come up with to save a tiny amount of space such as a few hundred MB to be a complete waste of time, since the swap file can very likely just end up eating the space you saved anyway.

ghporter · Feb 12, 2009, 08:54 PM

You say you "erased" files, but generally Mac users just put things they don't need in the Trash. This does not "erase" anything, but rather just marks those files as "deleted." They still exist and can still be accessed. When you empty the Trash, that doesn't necessarily clear that space, either.

I typically use "Secure Empty Trash" instead of just "Empty Trash". Secure Empty WIPES the space used by the deleted files and marks that space as available. I usually end up with noticeably more space when I use Secure Empty, because there are hidden files in the Trash all the time, and Secure Empty takes care of them too.

AKcrab · Feb 12, 2009, 09:51 PM

Originally Posted by ghporter

..., because there are hidden files in the Trash all the time, and Secure Empty takes care of them too.

What? How do hidden files get in the trash if they are hidden?

I just checked my trash; no hidden stuff.

steve626 · Feb 12, 2009, 11:41 PM

Originally Posted by ghporter

... When you empty the Trash, that doesn't necessarily clear that space, either.

... Secure Empty WIPES the space used by the deleted files and marks that space as available. I usually end up with noticeably more space when I use Secure Empty, because there are hidden files in the Trash all the time, and Secure Empty takes care of them too.

That doesn't sound right.

Empty trash doesn't ... really ... empty the trash? And can you somehow see these hidden files that are still there after emptying the trash ... but aren't (but are) visible? So the hidden files will basically stay around FOREVER unless you do Secure Empty Trash?

I have never done Secure Empty on a 2-yr old Mac and I looked via terminal to show hidden as well as unhidden files and there are no hidden files in my computer's trash (unless they are extra hidden hidden).

CharlesS · Feb 13, 2009, 12:12 AM

Empty Trash will delete everything in the Trash folders, whether they're invisible or not.

ghporter · Feb 13, 2009, 07:59 PM

I probably erred in saying "invisible" files were in the Trash-I have found that a lot of stuff winds up being deleted without going into the trash, and that stuff takes up space until you do something about it.

Yes, emptying Trash deletes all the files that were in it "permanently." But "emptying" the trash doesn't recover the space used by all files that were deleted, and those files are recoverable. Secure Empty seems to not only "really permanently" deletes files, but since those files are overwritten, their space is "recovered" by the system.

CharlesS · Feb 13, 2009, 08:52 PM

Empty Trash, Secure Empty Trash, rm, etc. all free up the space used by the file. The only exception I'm aware of is if a file has multiple hard links, in which case the file will still be there when deleted conventionally (I'm not sure exactly what would happen if you Secure Emptied a file with multiple hard links).

Art Vandelay · Feb 13, 2009, 09:06 PM

Glenn, I think you're getting confused about between file recoverability and file space reclamation. Like CharlesS mentioned, all the various means of deleting a file reclaim the space used by it. The directory table is updated to no longer reference the files and the space is reclaimed and made available. However, only Secure Empty Trash makes the file(s) unrecoverable by overwriting the sectors on the drive with zeroes multiple times. The other methods leave the file data intact on the hard drive sectors, but the space is still reclaimed in the directory table.

ghporter · Feb 14, 2009, 09:44 AM

I guess I haven't been paying close enough attention to available space numbers when I've looked at this. I has always "seemed" that Secure Empty reclaims more space than just Empty Trash.