Inodes after extending filesystem

Question

If I make a ext4 filesystem and add about 20% of extra inodes, how would this effect the inode count if later I extend the filesystem? Would the extended filesystem also automatically add an extra 20% inodes? Or would it add a normal amount of inodes? Would the inodes be spread across the filesystem evenly after extending the filesystem?

Answer 1

The number of inodes on ext4 will grow proportionally to number of blocks (in ratio dependent on "-i" flag to mke2fs). See ext4 wiki for details. So if you specified 20% more inodes than default by using "-i ", than yes it would grow by same extra 20% more than default ratio. However, if you specified 20% more inode manually using "-N number-of-inodes", then no, number of inodes would grow only by default ratio.