Department/Resources/User Directories

From A-State Computer Science Wiki
Jump to: navigation, search

Introduction

User Directories for the Computer Science Department may be accessed several different ways. If you are using a CS server (virtual or physical) the user directories are mounted automatically using NFS over a private network. If you would like to access your directory from any other source, you will need to use either SCP/SFTP or SSHFS. This document provides directions on how to use SSHFS.

SSHFS allows you to mount a remote directory locally using the SSH protocol. After the remote directory has been mounted it appears as a local directory.

Currently Windows support is only provided by the win-sshfs project. This project, while not dead, has limited support and known bugs that have yet to be addressed. For this reason win-sshfs has not been installed in the Labs. You are welcome to install win-sshfs on your personal machines, but please read the Known Bugs. If you do install it on your personal machines, be advise that when you start the program it may not open the GUI automatically. If it does not, start the program again.

System Requirements

You need to have FUSE installed on your local system in order to mount a directory using sshfs.

Installing FUSE

Mac OS

Install OSXFUSE

Windows

Install win-sshfs

Linux

Install the package sshfs or the appropriate sshfs package for your distribution.

Restrictions and Quotas

Restrictions

SCP/SFTP is the only available connection. You cannot ssh to the machine unless you are a CS Admin.

Quotas

All users have the following quotas in place.

  • 5GB of storage
    • You will start to receive warnings when you have used 4.8GB of space.
  • 250000 files
    • You will start to receive warnings when you are the owner of 100000 files.


Mounting your Remote Directory

Linux and Mac OS X

  • First create a local directory.
    mkdir ~/data
    
  • Now mount the remote directory.
    sshfs -o idmap=user $USER@magichat.cs.astate.edu:/home ~/data
    
    Information Icon.png

    You should replace $USER with your actual CS LDAP username.

    Your UID (User ID, the unique number that identifies you on the system) is not necessarily the same on the local host and the remote host. The filesystem only stores UIDs. When a program/command (e.g., ls) is executed, it looks up the UID and finds the username associated with it and displays the username not the UID (unless it cannot find the UID on the local system). In other words, if your local UID is 100 and your remote UID is 1001, the sshfs mounted directory may show different usernames for your files. However, this is not a problem since the ssh server on the remote machine is what is actually reading and writing files. Even though the local system may show a different UID, any changes are done through the ssh server on the remote host which will use the correct UID. To help with this the option idmap=user ensures that the files owned by the remote user are owned by the local user.

Unmounting your Remote Directory

Linux

Unmount the remote directory by issuing the command

fusermount -u ~/data

from the command-line.

Mac OS X

Unmount the remote directory using the eject icon in Finder or issuing the command

umount ~/data

from the command-line.