Free hard disk space reserved by Linux system "Go"

Http://www.cnblogs.com/ggjucheng/archive/2012/10/07/2714294.html

Objective

Most file systems retain some space for emergencies (such as a full disk space), which ensures that some critical applications (such as databases) have a bit of leeway when the hard disk is full, not crash immediately, giving monitoring systems and administrators a little time to detect. However, sometimes this part of the reserved hard disk space is a bit wasteful. How do I release the space reserved for this part of the system?

On the Linux ext2/ext3/ext4 file system usually reserved 5% of hard disk space, if the hard disk is 4TB, it means that there is 200GB of space is wasted, we can tune2fs to change the default settings, such as only 1% of the space reserved. Could it be set to 0%? Sure, but not recommended.

To view the current hard disk space situation:

# Df-hfilesystem            Size  used Avail use% mounted on/dev/mapper/vg_cloud22-lv_root                       32G  1.1G   30G   4%/tmpfs                  24G     0   24G   0%/dev/shm/dev/sda1             485M   68M  392M  15%/boot/dev/ Mapper/vg_cloud22-lv_home                      3.2G   70M  2.9G   3%/home/dev/sdd1            1008G  161G  797G  17%/var/cloud

To adjust the/DEV/SDD1, only 1% of the space is reserved:

# tune2fs-m 1/DEV/SDD1TUNE2FS 1.41.12 (17-may-2010) Setting reserved blocks percentage to 1% (2684381 blocks)

After adjusting to view the freed hard disk space, found that more 838-797=41GB space:

# Df-hfilesystem            Size  used Avail use% mounted on/dev/mapper/vg_cloud22-lv_root                       32G  1.1G   30G   4%/tmpfs                  24G     0   24G   0%/dev/shm/dev/sda1             485M   68M  392M  15%/boot/dev/ Mapper/vg_cloud22-lv_home                      3.2G   70M  2.9G   3%/home/dev/sdd1            1008G  161G  838G  17%/var/cloud

Transfer from http://www.vpsee.com/2012/09/release-linux-system-disk-space-using-tune2fs/

Free hard disk space reserved by Linux system "Go"