Mount File System

1. file system can be available after mounting.   I love u, WuHan.
2. Mount
        2.1 mount /dev/sdb2 /mnt/
            mount without any option will list all the mount file system
              -t filesystemTYPE
              -o optional,sepeatede by ,
                    ro/rw
                    sync no cache when writing data to disk
                    async default
                    noatime do not update file access time
                    atime
                    remount
3.Umount
        3.1 umount /dev/sdb3 & umount /mnt
             makes no difference.
        3.2 fuser -m /mnt list which process is using the file system
        3.3 lsof /mnt list all the opening file of system.
4. Mount auto
        4.1 modify /etc/fstab file. each line.

        4.2 Format

            /dev/sdb3 /mnt ext4 default

            label will replace /dev/sdb3 0.0 (dump & fsck), mount -a will mount all the lists line of file /etc/fstab