WiredRevolution.com » shared filesystem

Mount a VirtualBox shared folder inside a guest VM

Ryan — Thu, 09 Sep 2010 15:42:23 +0000

VirtualBox makes it easy to share folders between the host OS and various guest virtual machines, but it can be difficult to remember the exact way to go about mounting the shared folder within a guest VM. Here is the way to do it correctly.

First off make sure you have installed VirtualBox guest additions.

Switch to root or use sudo.
$ su -

Create the directory and mount the shared folder to the mount point of your choice. Use the shared name you assigned to it when you originally created the shared folder, in this case it is “virtualbox_share”.
# mkdir /media/share # mount virtualbox_share -t vboxsf /media/share

You can have this automatically mounted by adding the following line in /etc/fstab
virtualbox_share /media/share vboxsf defaults 0 0

Unfortunately the share will be owned by root. To make it owned and therefore writeable by a user use the following line instead. Replace the uid and gid with your information.
virtualbox_share /media/share vboxsf defaults,uid=500,gid=500 0 0

Here’s how to find your uid:
id -u username

And gid:
id -g username

Share a remote filesystem over SSH

Ryan — Wed, 25 Mar 2009 12:25:24 +0000

You may already be familiar with NFS and Samba for sharing files over a network. While these are both great distributed filesystem solutions, they require extra configuration and setup overhead in order to get them to work. If you want quick and easy access to a remote filesystem then SSHFS may be your best shot.

SSHFS (Secure SHell FileSystem) is a file system for Linux capable of operating on files on a remote computer using just a secure shell login. It is based on sftp (SSH File Transfer Protocol). Setup is easy on the server side, since most servers support SSH out of the box there is nothing to do. On the client side, mounting the filesystem is as easy as logging in with SSH. The end user can seamlessly and securely interact with remote files as if they were local to your machine.

Advantages of SSHFS over NFS/Samba:

Utilizes SSH and is therefore very secure.
Allows secure access to remote filesystems outside of your local network.
Requires no special configuration on the server side.

Disadvantages:

Slightly slower, although the difference is fairly small.
Does not show filesystem usage statistics.
Requires a user account on the server side.
Not a true distributed file system, single point to point sharing.

Setup

The first step is to install SSHFS.

In Ubuntu:

$ sudo apt-get install sshfs

or in Gentoo:

$ sudo emerge -av sshfs-fuse

Create the mount point on your local machine. This is where you are going to access the remote filesystem.

$ sudo mkdir /mnt/share

Your user must have permission to access this mountpoint.

$ sudo chown ryan /mnt/share

Start Sharing

Now use the sshfs command to mount the remote filesystem. If the username is different on the server you are connecting, use the “username@host:” format, otherwise you can simply specify “host:”.

$ sshfs ryan@fileserver:/remote/share /mnt/share

If you are not using keys with SSH you will be prompted for a password.

ryan@fileserver's password:

Once you are finished you can easily unmount the filesystem.

as regular user:

$ fusermount -u /mnt/share

or as root:

$ sudo umount /mnt/share

Configuration

You can add an entry for this share to /etc/fstab to make the mounting process more seamless.

sshfs#ryan@fileserver:/remote/share /mnt/share fuse user,noauto 0 0

user – allow any user to mount this share.
noauto – stop the shared directory from being automatically mounted at startup.

If you want it automatically mounted, ensure that your SSH configuration uses keys and not passwords so it doesn’t ask for a password at startup. Once keys are in use you can safely remove the noauto option.

With fstab updated you can now mount the share as a normal user with this simple mount command. Again, if ssh is configured to use passwords you will still be prompted for one.

$ mount /mnt/share

Skip network filesystems when searching with find

Ryan — Mon, 19 Jan 2009 16:45:06 +0000

When you run the find command on the root directory of a system you may want to exclude all network filesystems and confine your search to only your local machine. The benefits of this are obvious as it will save you a great amount of time especially if the mounted filesystem is very large.

Luckily the find command provides this ability with the ‘-xdev‘ or ‘-mount‘ options.

For example:

$ find / -xdev -name myfile.txt

This command will recursively search for myfile.txt starting in your root directory and skip all externally mounted filesystems.