"Lost space" for Ext3 and Ext4 file systems on hard drive
Is it normal for ext3 and ext4 to have "lost space", ie space reported by the system as "free" but "not available"?
On my system, I have one partition for Windows XP formatted NTFS. One /home partition, formatted ext3, and the Linux filesystem formatted ext4 (I created my separate /home partition before ext4 came along).
My system monitor is showing the NTFS partition as 10.9GB free, 10.9GB available; a memory stick I have mounted at the moment (vfat) is showing 7.7GB free and available. But the ext3 filesystem shows 1.1GB free but only 573.8MB available. The ext4 filesystem shows 13GB free but only 12.1GB available.
Is this lost space the penalty you pay for using ext3/4 filesystems, or does this lost space represent bad sectors? I am nervous about using any disk analysis or repair tools, as I am aware that one wrong move could be disastrous!
Does anyone have any advice? Thank you.