m.2 Drive reporting filled up when there is plenty of reported space.

Windows 10 1903 , brand new install build Build 18363. (new)


Have 370 gig partition, on an m.2 . As you can see from the chkdsk output below, I have 155 gig available. No errors reported

Also using compression, which should give me even more actual storage of data. Always has.

Just went to write a file of only 112 gig ,and it stopped half way through with an 'out of space' error , so only 50 gig or so caused this ???

Have system restore turned off for this partition. System Restore Volume reports zero bytes, but not sure that is accurate.


What is going on with this ?






C:\Windows\system32>chkdsk d:
The type of the file system is NTFS.
Volume label is New Volume.

WARNING! /F parameter not specified.
Running CHKDSK in read-only mode.

Stage 1: Examining basic file system structure ...
49408 file records processed.
File verification completed.
20808 large file records processed.
0 bad file records processed.

Stage 2: Examining file name linkage ...
32 reparse records processed.
50746 index entries processed.
Index verification completed.
0 unindexed files scanned.
0 unindexed files recovered to lost and found.
32 reparse records processed.

Stage 3: Examining security descriptors ...
Security descriptor verification completed.
669 data files processed.

Windows has scanned the file system and found no problems.
No further action is required.

327678975 KB total disk space.
172295956 KB in 21545 files.
5152 KB in 671 indexes.
0 KB in bad sectors.
126123 KB in use by the system.
65536 KB occupied by the log file.
155251744 KB available on disk.

4096 bytes in each allocation unit.
81919743 total allocation units on disk.
38812936 allocation units available on disk.

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Just ran another test, copying an existing file and had no problem filling up 112 gig .

So the size error might have been some other issue, copying from an external drive.

Trying that again

I see whats going on.

The drive starts out with 175 gig of free space, and reserves 113 gig for the file Im copying. Started out with 60 or so Gig free as the copy began.

Problem is, The free space is ticking down as the file is copied. Big time. Talking 30 gig less actual free space showing and Im only 70% through the copy ...

WT#? Is this an artifact of compression??? Been using Windows 7 forever, and never remember this problem.

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Plankton said:

Are you sure the file is that big....112 gig. If so that's 1/3 of your SSD. That's a big file. 112 gig of 155 gig left leaves 43 gigs. Depending on MFG.....the trigger limit for running out of space is different.

The SSD is 500 gig, this is a 327 gig partition. I tested an internal copy without compression, and I didn't see this problem. so I'm thinking thats causing it , though I don't know why.

Any NTFS compression gurus here?

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Learn something new every day.

Turns out , it's generally a bad idea to compress a file that large, unless there's a lot of compressible data. In this case, there wasn't.

Cause's problems like I reported.

Solution, don't use compression on the file !

Also, I see the copy itself it now at least TWICE as fast, maybe more, uncompressed . Not sure why, as the CPU is a RYZEN 3700x, so it cant be the compression algo alone slowing it up.