Does using LVM cause you to lose filesystem space twice? Lot's of missing space after lvextend

Your lvextend command is incorrect. You told it to 'make the logical volume the size of 100% of the free space.'

I think you intended to say 'make the logical volume GROW by the size of 100% of the free space.'

lvextend -l 100%FREE /dev/VolGroup00/LogVol01

Should be:

lvextend -l +100%FREE /dev/VolGroup00/LogVol01

Note the '+'.