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Question

Slowly disappearing free space on SSD

Apr 30, 2015 4:05PM PDT

I have a Samsung 840 EVO SSD (250GB) and have noticed slowly disappearing free space on the drive. The drive is set as a boot drive on a Windows 7 system (user folders are on a regular HDD). The drive has multiple partitions, but I am only talking about a 200GB partition for booting Windows (Windows folder, Program Files folder, ProgramData folder, etc), not any recovery partitions, boot blocks, or overprovisioning space (which is on a different partition completely). I began noticing that space appeared to be decreasing at a fairly regular rate (about 1GB every day or so). In my initial research, I found this is apparently a common problem and likely does not only affect Samsung drives, but drives by all manufacturers, and appears to happen not only with Windows systems, but OS X and Linux as well.

It initially seemed that the vanishing space was due to Windows temp files, system restore files, and the like. System restore on this partition had been disabled when I installed it. I then did a file size count and it appeared that there was around 30GB of space unaccounted for. I tried running chkdsk and it matched what Windows had reported for used & free space and found no issues. Time for some bigger guns.

I tried GPartEd and again got the same used & free space numbers Windows reported. My worry was there was some growing "super hidden" file(s), maybe even some insidious malware taking up space (not long ago on a different system, I had this very problem where there was a hypervisor OS installed above Windows on a hidden partition with full remote control). I still could not believe there was 30GB worth of files from normal Windows operations that are unaccounted for.

Since GPartEd runs under Linux, I can bypass all of the Windows security restrictions and see all the files, which included about 100MB worth of files in the "empty" system restore folder. I selected every single file and folder on the root of the partition and did a "Properties" to get a count. Again, the byte count of all the files was about 30GB below the reported used space. Again, I'm doing this check under a Linux boot, so every single folder and file is accessible. I then ran Disk Usage Analyzer, and again the sum total of all the files was about 30GB short of the reported used space.

I then tried both WinDirStat and TreeSize (free) under Windows. They both found and "unknown" area the size of my "missing" space. The space show as one large block and was completely inaccessible with no attached file names. As if this was an allocated area of nothing. I even tried running both apps under a SYSTEM login, and STILL could not determine what this 30GB block of used space was.

My next thought was this might be some "garbage collection" issue with the SSD. Maybe the TRIM function is not working right. I ran the Performance Optimization in the Samsung Magician. There was no change. I tried forcing Windows to run its own TRIM routine. No change. I even tried running the drive without a data cable for several hours (but with the power cable connected) in hopes the internal firmware would do its thing with an idle drive. No change.

I then cleared all the temp files and browser caches. I recovered some space, but the amount of used space went down as the free space went up by the same amount, so that 30GB block is still unaccounted for. I then kept a close eye on the used space, I still see the space creeping down. I started my investigation into this at the beginning of the month. Since then, the missing space has grown from about 30GB to about 70GB.

As I mentioned, I did a lot of digging around and most of the answers explained the missing files as due to the Windows system restore folders, page files, hibernation files, and other files, which seemed to satisfy the poster, but did not answer it correctly. I also saw this issue posted in Apple and Linux boards, but they had no explanations of what was the cause of the missing space nor a way to recover it. And again, this appears to be a fundamental issue with SSDs as the threads I've read mention a number of different brand drives.

Anyone else experience this? Anyone have a solution?

Discussion is locked

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Answer
Sorry no.
May 1, 2015 12:12AM PDT

But did you turn off Windows automatically scheduled defrag to cut down wear on the SSD?

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I read it over twice
May 1, 2015 12:32AM PDT

And we know Windows just keeps on hiding stuff. I'd only be concerned if the drive total space was falling. Free space however, even on rusty HDDs was somewhat of a foggy area to nail down. Given the time one would have to invest to find Waldo, most never invest the time.
Bob

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Missing points
May 1, 2015 12:47PM PDT

1 - Yes, defrag is off, but this isn't my issue.

Yes, Windows does hide stuff. But I must reiterate:
- I bypassed Windows altogether by booting into Linux to look at all the files (Linux ignores any Windows security bits and so all files are accessible; I frequently use Linux tools to get rid of the more stubborn malware in Windows).
- In my research, this problem does not appear to OS related since I've seen people reporting the same mysterious free space loss on OS X and Linux.

My gut feeling is this is some fundamental drive issue where internal garbage collection is not freeing up areas of the drive. The problem is within the partition, not the entire drive. I also have not experienced creeping space loss on traditional HDD drives (and those same Linux tools don't have a dependency between used space and file size count).

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Just so we're clear.
May 1, 2015 1:01PM PDT

You know that the MFT grows and never shrinks. That issue has been kicking around since NT 3.0 or later.

I can't know how deep you can dive on Windows but it's a known issue that MSFT has been strangely mum about for decades.
Bob

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Reading material.
May 2, 2015 3:18AM PDT
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Answer
RE: SSD
May 2, 2015 3:04AM PDT

Jeff,

For all solid state drive questions, please either email support@totalts.com or call 1-800-SAMSUNG > Press 1 for consumer > Press 1 for new inquiry > 4 for PC > 5 for Drives & Memory > 1 for Solid State Drive. The SSD support team is available 9 AM - 9 PM Mon-Fri.

Regards,

HD Tech

We look forward to hearing from you!

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Answer
indexing
May 15, 2015 7:22AM PDT

I had a problem like this, windirstat couldn't figure it out until I ran windirstat as an administrator. After I did that, I found a 131GB file called Windows.edb in c:\program data\microsoft\search\data\applications\windows. It was the windows search indexing cache. To delete it, I did this:
(1) Search for "Indexing Options" Open it.
(2) Search "services" (or run "services.msc", or use task manager's services tab) and find "Windows Search". Stop the service.
(3) Delete the Windows.edb file from "program data\microsoft\search\data\applications\windows"
(3.5)*optional* For SSDs, you may not want to index your drive - a search will be quick without it and it's a waste of space as well as unnecessary wear and tear on your SSD. In the indexing options box, click "Modify" and uncheck any SSDs you may have. You may want to keep the start menu indexed - it should show up as an included location. If you have any libraries located on your SSD, remove them from the included locations. If you have another drive on your computer that is larger than your SSD, you may want to store the index file there. Click "Advanced" and under "index location" click "select new."
(4) Click "Advanced" in the already-open "Indexing Options" panel after the service restarts itself,then click rebuild.
Hope this helps.