# su root  --- You must be root before you begin, else you can't mount files
umount bar
dd if=/dev/zero of=foo bs=1000000 count=1
mkfs -t ext2 foo
mkdir bar
mount -oloop foo bar
perl -e 'for(1..1000000) { print "SCO sucks\n" }' > bar/sco
sync
ls -la bar
rm -f bar/sco 
umount bar
strings foo |grep SCO |head -100

dd if=/dev/zero of=foo bs=1000000 count=1
mkfs -t ext2 foo

mount -oloop foo bar
perl -e 'for(1..1000000) { print "SCO sucks\n" }' > bar/sco
sync
shred bar/sco
sync
umount bar
strings foo |grep SCO

dd if=/dev/zero of=foo bs=10000000 count=1 
mkfs -t ext3 foo
mount -oloop foo bar
perl -e 'for(1..10000000) { print "SCO sucks\n" }' >bar/sco
sync
shred bar/sco
sync
rm -rf bar/sco
umount bar
strings foo |grep SCO

mount -oloop foo bar
perl -e 'for(1..1000) { print "SCO sucks\n" }' >bar/sco
perl -e 'for(1..1000) { print "SCO sucks\n" }' >bar/sco2
perl -e 'for(1..1000) { print "SCO sucks\n" }' >bar/sco3
perl -e 'for(1..1000) { print "SCO sucks\n" }' >bar/sco4
perl -e 'for(1..1000) { print "SCO sucks\n" }' >bar/sco5
perl -e 'for(1..1000) { print "SCO sucks\n" }' >bar/sco6
sync
shred bar/sco*
sync
strings bar/sco* |grep SCO
umount bar
strings foo |grep SCO