Ubuntu – NTFS -> EXT4 migration, where did 120 GB go

ext4filesystemntfs

wim@wim-ubuntu:~/Desktop$ mount | grep media
/dev/sdc1 on /media/data type ext4 (rw,nosuid,nodev,uhelper=udisks)
/dev/sdb1 on /media/wd type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096,default_permissions)
wim@wim-ubuntu:~/Desktop$ df | grep media
/dev/sdc1            1922858352 1824822680    360072 100% /media/data
/dev/sdb1            1953512000 1825392384 128119616  94% /media/wd
wim@wim-ubuntu:~/Desktop$ df -h | grep media
/dev/sdc1             1.8T  1.7T  352M 100% /media/data
/dev/sdb1             1.9T  1.8T  123G  94% /media/wd

I am moving my data from an NTFS drive to an ext4 drive. On the NTFS volume I had 122.2 GB free, then after copying with rsync (excluding a couple of unneeded NTFS files in System Volume Information), I have only 351.6 MB free.

The hard disks are identical WD 2TB drives. I created the EXT4 partition with gparted, is there any reason why the ext4 would have 30653648 less blocks on it?

Output of sudo fdisk -l:

Disk /dev/sdc: 2000.4 GB, 2000397852160 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00bb4cbc

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1      243201  1953512001   83  Linux

Disk /dev/sdb: 2000.4 GB, 2000397852160 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xcefa6110

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1      243201  1953512001    7  HPFS/NTFS

Best Answer

After some fiddling about, I was able to reclaim a large amount of space with tune2fs:

wim@wim-ubuntu:~/Desktop$ df -h | grep sdc
/dev/sdc1             1.8T  1.7T  352M 100% /media/data
wim@wim-ubuntu:~/Desktop$ sudo tune2fs -l /dev/sdc1 | grep 'Reserved block count'
Reserved block count:     24418900
wim@wim-ubuntu:~/Desktop$ sudo tune2fs -m 0 /dev/sdc1
tune2fs 1.41.14 (22-Dec-2010)
Setting reserved blocks percentage to 0% (0 blocks)
wim@wim-ubuntu:~/Desktop$ sudo tune2fs -l /dev/sdc1 | grep 'Reserved block count'
Reserved block count:     0
wim@wim-ubuntu:~/Desktop$ df -h | grep sdc
/dev/sdc1             1.8T  1.7T   94G  95% /media/data

Apparently linux reserve 5% of new partitions for the root user and system services, so that when you run out of disk space, root can still log in and clean stuff up with system services running ok. Seems kind of bananas to me when the system services only need a hundred meg or so, and 5% of a 2TB drive is a $h17load more than that.. shrugs

This left me with 93.5 GB free, which still leaves about 30 gig unaccounted for, so if anyone has any more ideas feel free to chip in!