size difference in partition and NTFS file system

m4rtin · 05-03-2012, 11:01 AM

I have a server which has one primary 15GB partition. On this partition there is a NTFS file system. File system was created with Windows Server 2003 installer. Any ideas why there is a >1GB difference(13.96983GB VS 15.00003GB) between partition size and file system size? Why is partition so much larger?

Code:

root@Microknoppix:~# fdisk -lu

Disk /dev/sda: 80.0 GB, 80026361856 bytes
240 heads, 63 sectors/track, 10337 cylinders, total 156301488 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xf155f155

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *          63    31457343    15728640+   7  HPFS/NTFS
root@Microknoppix:~# printf '(%s*%s)/(%s^%s)\n' 31457343 512 1024 3 | bc -l
15.00003004074096679687
root@Microknoppix:~# ntfsinfo -m /dev/sda1
Volume Information 
	Name of device: /dev/sda1
	Device state: 11
	Volume Name: 
	Volume State: 1
	Volume Version: 3.1
	Sector Size: 512
	Cluster Size: 4096
	Volume Size in Clusters: 3662108
MFT Information 
	MFT Record Size: 1024
	MFT Zone Multiplier: 1
	MFT Data Position: 24
	MFT Zone Start: 786432
	MFT Zone End: 1244195
	MFT Zone Position: 786432
	Current Position in First Data Zone: 1244195
	Current Position in Second Data Zone: 0
	LCN of Data Attribute for FILE_MFT: 786432
	FILE_MFTMirr Size: 4
	LCN of Data Attribute for File_MFTMirr: 1831054
	Size of Attribute Definition Table: 2560
FILE_Bitmap Information 
	FILE_Bitmap MFT Record Number: 6
	State of FILE_Bitmap Inode: 0
	Length of Attribute List: 0
	Attribute List: (null)
	Number of Attached Extent Inodes: 0
FILE_Bitmap Data Attribute Information
	Decompressed Runlist: not done yet
	Base Inode: 6
	Attribute Types: not done yet
	Attribute Name Length: 0
	Attribute State: 3
	Attribute Allocated Size: 458752
	Attribute Data Size: 457768
	Attribute Initialized Size: 457768
	Attribute Compressed Size: 0
	Compression Block Size: 0
	Compression Block Size Bits: 0
	Compression Block Clusters: 0
root@Microknoppix:~# printf '(%s*%s)/(%s^%s)\n' 3662108 4096 1024 3 | bc -l
13.96983337402343750000
root@Microknoppix:~#

If I compare partition and file system size for ext[34] partitions it's almost identical. For example in another machine I have 9.31348GB primary partition and on this partition there is a 9.31250GB ext4 file system

Any ideas?

pan64 · 05-04-2012, 02:09 AM

I checked my ntfs drive and the two sizes were exactly the same. So maybe you have resized your partition or made another trick?
What I could say: fdisk doesn't take care about the filesystem, it reports the size of the partition. ntfsinfo reports the size of the formatted filesystem and does not take care about the underlying partition.

syg00 · 05-04-2012, 02:20 AM

If it worries you, simply run ntfsresize - it'll fill the partition.

m4rtin · 05-07-2012, 10:31 AM

syg00, pan64:

Thanks! I did "ntfsresize -v /dev/sda1" and now my NTFS file system size is 14.999996GB