This is driving me mad. When copying files from the 466Gb disk (with 31Gb free) to a 531Gb empty LVM, I am running out of space. Why is that? Here's my df -h after copying from /var/lib/backuppc_old to /var/lib/backuppc. This is totally baffling. Both filesystems are reiser 3.

Code:
> df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2             7.8G  2.5G  5.1G  33% /
varrun                506M  212K  506M   1% /var/run
varlock               506M     0  506M   0% /var/lock
udev                  506M   60K  506M   1% /dev
devshm                506M     0  506M   0% /dev/shm
/dev/sdc1             466G  436G   31G  94% /var/lib/backuppc_old
/dev/mapper/backupvg-backuplv
                      531G  531G     0 100% /var/lib/backuppc
Here's my fdisk -l
Code:
> fdisk -l

Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x90909090

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1         243     1951866   82  Linux swap / Solaris
/dev/sda2             244        1275     8289540   83  Linux
/dev/sda3            1276        9729    67906755   8e  Linux LVM

Disk /dev/sdb: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00040576

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1       60801   488384001   8e  Linux LVM

Disk /dev/sdc: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x28a90443

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1       60801   488384001   83  Linux
Does anyone have any idea how I can fix this weird problem? Thanks!!