Chapter 27 . Running a File Servers (Web hosting e commerce) 729
Chapter 27 . Running a File Servers 729 Unmounting NFS File Systems After an NFS file system is mounted, unmounting it is simple. You use the umount command with either the local mount point or the remote file system name. For example, here are two ways you could unmount maple:/tmp from the local directory /mnt/maple. # umount maple:/tmp # umount /mnt/maple Either form works. If maple:/tmp is mounted automatically (from a listing in /etc/ fstab), the directory will be remounted the next time you boot Linux. If it was a temporary mount (or listed as noauto in /etc/fstab), it won t be remounted at boot time. The command is umount, not unmount. This is easy to get wrong. If you get the message device is busy when you try to unmount a file system, it means the unmount failed because the file system is being accessed. Most likely, one of the directories in the NFS file system is the current directory for your shell (or the shell of someone else on your system). The other possibility is that a command is holding a file open in the NFS file system (such as a text editor). Check your Terminal windows and other shells, and cd out of the directory if you are in it, or just close the Terminal windows. If an NFS file system won t unmount, you can force it (umount -f /mnt/maple) or unmount and clean up later (umount -l /mnt/maple). The -l option is usually the better choice because a forced unmount can disrupt a file modification that is in progress. Other Cool Things to Do with NFS You can share some directories to make it convenient for a user to work from any of several different Linux computers on your network. Some examples of useful directories to share are: . /var/spool/mail By sharing this directory from your mail server and mounting it on the same directory on other computers on your network, users can access their mail from any of those other computers. This saves users from having to download messages to their current computers or from having to log in to the server just to get mail. There is only one mailbox for each user, no matter from where it is accessed. . /home This is a similar concept to sharing mail, except that all users have access to their home directories from any of the NFS clients. Again, you would Tip
If you are in need for chaep and reliable webhost to host your website, our recommendation is http web server services.