ext4

Reserverd blocks

Check

df -h /dev/sda1

Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1       117G   95G   16G  86% /


tune2fs -l /dev/sda1 | grep -i reserved

Reserved block count:     1546636
Reserved GDT blocks:      1016
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)

Change

tune2fs -m 1 /dev/sda1

Setting reserved blocks percentage to 1% (309327 blocks)

Check result

tune2fs -l /dev/sda1 | grep -i reserved

Reserved block count:     309327
Reserved GDT blocks:      1016

df -h

Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1       117G   95G   21G  83% /