Disk space disappeared?

[Krayzie135]

i have my drive partitioned and my "D" drive is for my files and random stuff. it says i have 80GB used but when i go into "properties" to check the size of everyting it is only around 40GB used. were did the other 40GB go?



http://www.hardfolding.com/ftag1.php/mem/147644.png (http://www.hardfolding.com?go=38&tm=33&id=147644)

[MrGuvernment]

control panel / administrative tools / computer management


did you move your virtual memory drive?


open a folder - tools / options / view / show hidden files and folders.

[drizzt81]

how big is the drive?

[Krayzie135]

i just formatted it yesturday but would still like to know what was up. internet cut out yestuday so couldnt post

its a 250GB HDD partitioned into 3 parts

C-50gb
D-100gb
E-100gb

[drizzt81]

at least 25 GB will go towards the MFT that NTFS uses. Also, the recycler and system restore may hold some more space captive.

[Xilikon]

Don't forget that even if you saved a bunch of 1 kb files, it will use blocks of bigger sizes with 16kb / 32 kb commonly used. 1 file will use 1 block, no matter if there is unused block space.

So 100 x 1 kb files could waste as much as 3200 kb (compared to the original 1 kb).

that's where the waste will come. If you only have big files, you are wasting less space.

[drizzt81]

Don't forget that even if you saved a bunch of 1 kb files, it will use blocks of bigger sizes with 16kb / 32 kb commonly used. 1 file will use 1 block, no matter if there is unused block space.

So 100 x 1 kb files could waste as much as 3200 kb (compared to the original 1 kb).

that's where the waste will come. If you only have big files, you are wasting less space.
Not on NTFS:

http://en.wikipedia.org/wiki/Ntfs

"In NTFS, everything that has anything to do with a file (file name, creation date, access permissions and even contents) is stored as metadata" (my emphasis)


http://www.pcguide.com/ref/hdd/file/ntfs/archMFT-c.html

"When any file or directory is created on the NTFS volume, a record is created for it within the MFT. The size of each record in the MFT seems to be a matter of some controversy; the best that I can tell is that each record is equal to the cluster size of the volume, but with a minimum of 1,024 bytes and a maximum of 4,096. (Meaning that even if 512 byte clusters are used, each MFT record is still 1,024 bytes, and even if clusters greater than 4,096 bytes are used, each MFT record is limited to 4,096 bytes.) However, some sources say that the size of each MFT record is fixed at either 1,024 or 2,048 bytes."

"Remember that under NTFS, there is no special distinction between the data in a file and the attributes that describe the file--the data itself is just the contents of the "data attribute". This has an interesting implication for small files. If the amount of space required for all of the attributes of a file, including the data it contains, is smaller than the size of the MFT record, the data attribute will be stored resident--within the MFT record itself. Thus, such files require no additional storage space on the volume, and also do not require separate accesses to the disk to check the MFT and then read the file, which improves performance."

Since the MFT is a single file with a fixed record size, every file less than 1KB will not take up a "cluster size" but only 1KB. Large files (> 1 KB) will waste this amount of space:
(FileSize - (~1KB)) % ClusterSize

from the horse' mouth:
http://technet2.microsoft.com/WindowsServer/en/library/81cc8a8a-bd32-4786-a849-03245d68d8e41033.mspx?mfr=true

"File and folder records are 1 KB each and are stored in the MFT, the attributes of which are written to the allocated space in the MFT. Besides file attributes, each file record contains information about the position of the file record in the MFT."

to op:
"To prevent the MFT from becoming fragmented, NTFS reserves 12.5 percent of volume by default for exclusive use of the MFT. This space, known as the MFT zone, is not used to store data unless the remainder of the volume becomes full."

[protias]

so drizzt, am i correct in thinking with the metadata taking up 12.5% of the drive, this is part of how windows formats the drive? or am i just making wild accusations?