Thursday, August 20, 2015

ext4 block reservation

The filesystem ext4 has a feature called block reservation. When you create an ext4 filesystem then 5% of your available space will be reserved for block reservation by default. For an 20GB filesystem it is only 1GB of reserved space. But if you have an 1.5TB filesystem then 5% are about 75GB already. And that is my case. I have a 1.5TB partition with an ext4 filesystem: