how to extend knoppix-data.img. see details http://knoppix.net/forum/threads/28316-resizing-knoppix-data.img?p=120365

extend_knoppix-data.img.log.sh

# at the 1st, fix TZ and time
$ sudo dpkg-reconfigure tzdata # -> to Asia/Tokyo UTC+9 from UTC
$ sudo aptitude update
$ sudo aptitude install ntpdate
$ sudo ntpdate ntp.nict.jp


# how to resize knoppix-data.img
# c.f. http://knoppix.net/forum/threads/28316-resizing-knoppix-data.img?p=120365

# backup persistent image
$ cp -v knoppix-data.img /media/sdc5/_backup/
#`knoppix-data.img' -> `/media/sdc5/_backup/knoppix-data.img'

# check filesystem
$ sudo e2fsck -fy knoppix-data.img
#e2fsck 1.42.4 (12-Jun-2012)
#Pass 1: Checking inodes, blocks, and sizes
#Deleted inode 17 has zero dtime.  Fix? yes
#...
#Pass 2: Checking directory structure
#Pass 3: Checking directory connectivity
#Pass 3A: Optimizing directories
#Pass 4: Checking reference counts
#Pass 5: Checking group summary information
#Block bitmap differences:
#...
#knoppix-data.img: ***** FILE SYSTEM WAS MODIFIED *****
#knoppix-data.img: 17943/127488 files (5.2% non-contiguous), 392725/509440 blocks

# 1G extend to img by zerofill
$ sudo dd if=/dev/zero bs=1M count=1000 >> knoppix-data.img
#1000+0 records in
#1000+0 records out
#1048576000 bytes (1.0 GB) copied, 69.947 s, 15.0 MB/s
$ ll -h | grep knoppix-data.img
#...
#-rwxrwxrwx 1 knoppix knoppix 3.0G Feb 4 01:41 knoppix-data.img
#...

# resize filesystem
$ sudo resize2fs knoppix-data.img
#resize2fs 1.42.4 (12-Jun-2012)
#Resizing the filesystem on knoppix-data.img to 765440 (4k) blocks.
#The filesystem on knoppix-data.img is now 765440 blocks long.

resized.log

$ mount -l | column -t
rootfs            on  /                    type  rootfs                 (rw,relatime)
proc              on  /proc                type  proc                   (rw,relatime)
sysfs             on  /sys                 type  sysfs                  (rw,relatime)
/dev/sdb1         on  /mnt-system          type  vfat                   (rw,relatime,fmask=0000,dmask=0000,allow_utime=0022,codepage=cp850,iocharset=iso8859-1,shortname=winnt,errors=remount-ro)                            [KNOPPIX]
tmpfs             on  /ramdisk             type  tmpfs                  (rw,relatime,size=2486272k)
/dev/cloop        on  /KNOPPIX             type  iso9660                (ro,relatime)                                                                                                                                        [KNOPPIX]
/dev/loop0        on  /KNOPPIX-DATA        type  ext2                   (rw,relatime,errors=continue,user_xattr,acl)
unionfs           on  /UNIONFS             type  aufs                   (rw,relatime,si=2790346c,noplink)
unionfs           on  /usr                 type  aufs                   (rw,relatime,si=2790346c,noplink)
unionfs           on  /home                type  aufs                   (rw,relatime,si=2790346c,noplink)
usbfs             on  /proc/bus/usb        type  usbfs                  (rw,relatime)
tmpfs             on  /UNIONFS/var/run     type  tmpfs                  (rw,relatime,size=10240k)
tmpfs             on  /run                 type  tmpfs                  (rw,relatime,size=20480k)
tmpfs             on  /UNIONFS/var/lock    type  tmpfs                  (rw,relatime,size=10240k)
tmpfs             on  /UNIONFS/var/log     type  tmpfs                  (rw,relatime,size=102400k)
tmpfs             on  /tmp                 type  tmpfs                  (rw,relatime,size=2097152k)
udev              on  /dev                 type  tmpfs                  (rw,relatime,size=20480k)
tmpfs             on  /dev/shm             type  tmpfs                  (rw,relatime,size=2097152k)
devpts            on  /dev/pts             type  devpts                 (rw,relatime,mode=1777)
/dev/sdb2         on  /media/sdb2          type  vfat                   (rw,nosuid,nodev,relatime,uid=1000,gid=1000,fmask=0000,dmask=0000,allow_utime=0022,codepage=cp932,iocharset=utf8,shortname=winnt,errors=remount-ro)  [DATA]
gvfs-fuse-daemon  on  /home/knoppix/.gvfs  type  fuse.gvfs-fuse-daemon  (rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)

$ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sdb1       3.6G  3.6G  9.1M 100% /mnt-system
tmpfs           2.4G     0  2.4G   0% /ramdisk
/dev/cloop      1.7G  1.7G     0 100% /KNOPPIX
/dev/loop0      2.9G  1.5G  1.5G  52% /KNOPPIX-DATA
unionfs         2.9G  1.5G  1.5G  52% /UNIONFS
unionfs         2.9G  1.5G  1.5G  52% /usr
unionfs         2.9G  1.5G  1.5G  52% /home
tmpfs            10M  216K  9.8M   3% /UNIONFS/var/run
tmpfs            20M  2.8M   18M  14% /run
tmpfs            10M     0   10M   0% /UNIONFS/var/lock
tmpfs           100M  144K  100M   1% /UNIONFS/var/log
tmpfs           2.0G   32K  2.0G   1% /tmp
udev             20M  4.0K   20M   1% /dev
tmpfs           2.0G     0  2.0G   0% /dev/shm
/dev/sdb2       3.9G  952K  3.9G   1% /media/sdb2