How to grow filesystem to use unallocated space in partition?

  • If gparted only has to extend the partition or filesystem into unused space (immediately following the partition), then it should be safe to let it extend the partition and/or fs.

  • If, however, it has to MOVE any partitions around to make space for resizing, you'll have to boot with a gparted Live CD

  • See the man page for resize2fs (which is the command-line tool gparted will use to grow an ext2, ext3, and ext4 filesystem) for more details about resizing those filesystems.

    For ext2/3/4, growing a filesystem is generally not a problem and can safely be done while the fs is mounted.

    Shrinking a filesystem, however, is more troublesome and should be done while the fs is unmounted. If it's the rootfs, that means booting to a rescue CD/USB/PXE etc.

BTW, both dd and cat are amongst the worst ways to copy a linux system to another hard disk. Use Clonezilla, that's what it's for.

sudo resize2fs /dev/sda6 

will solve your problem.