linux 内存使用

# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1              50G  1.9G   45G   5% /
tmpfs                 1.9G     0  1.9G   0% /dev/shm
/dev/sda3              77G  469M   73G   1% /opt

/etc/fstab

......
tmpfs                   /dev/shm                tmpfs   defaults,size=1g        0 0
......

mount -o remount /dev/shm
# mount -o remount,rw /dev/shm