Ubuntu 10.04: disk check at boot takes a long time

Solution 1:

As with most programs that show a progress percentage, this percentage is only a rough approximation. In the specific case of e2fsck (it's the same program for ext2, ext3 and ext4), the completion percentage is computed per pass and arbitrarily expressed in a range:

1. sequential scan of the inode table: 0–70%
2. check directory structure: 70–90%
3. check for directory connectivity: 90–92%
4. check reference counts: 92–95%
5. check block and inode bitmaps against on-disk bitmaps: 95–100%

So in your case the scan of the inode table is very fast, and the check of the directory structure takes a long time. I don't think this is cause for worry.