$ df -h /data/backup; sudo tune2fs -m 0 /dev/xvdc1; df -h /data/backup
Filesystem            Size  Used Avail Use% Mounted on
/dev/xvdc1            345G  233G   95G  71% /data/backup
tune2fs 1.41.12 (17-May-2010)
Setting reserved blocks percentage to 0% (0 blocks)
Filesystem            Size  Used Avail Use% Mounted on
/dev/xvdc1            345G  233G  113G  68% /data/backup