Free Disk Space by Reducing Reserved Blocks Percentage

In a default install Linux reserves 5% of the disk space for privileged processes. It is a precautionary measure on part of Linux to keep up even after the file-system is filled up.

With this approach it allows root to conduct administrative activities on the partition and perhaps move some data off. However, this is most critical when the partition contains / or home directories. For pure data partitions, this is just lost space. Five percent of a 250Gb partition is 12.5 Gb. Especially in the case of large partitions, it is safe to set the reserved space to the minimum, which is one percent or even to 0 percent.

There are two ways through which you can adjust this reserve percentage

1) At the time of creation of file-system:

# mkfs.ext3 -m 1/dev/sda1 (replace sda1 with your partition name)

The above command creates a file system with only 1% of its space reserved for the root user.

2) After creation of file-system:

You can use tune2fs utility to reduce reserved blocks in ext2, ext3 as well as ext4 file-systems. To reduce reserved blocks to 1% use the following command:

# tune2fs -m 1 /dev/sda1 (replace sda1 with your partition name)

In a 1 TB hard drive you can save upto 37GB of space after applying this tweak.