How To: Network Trash on Ubuntu File Server (NAS) with SFTP (SSH + Fuse) and AFP (netatalk)

Now you are all set in the terminal.

There are a few more steps that need to be taken in order to begin utilizing Trash folders for the users on your system. For each method of connecting/utilizing the files on the server (through the command line, through sshFS, or AFP), the LD_PRELOAD option needs to be called for libtrash. Also, I recommend you use one of the Trash cleaning scripts (outlined below).

using libtrash with SFTP (sshFS)

I like to mount my home server remotely using sshFS (which utilizes FUSE). sshFS can be used on the Mac through the MacFUSE project or on Ubuntu through Places/Go to Server Menu on 7.04). To initialize libtrash, we need to modify which script is called when the file system is first mounted to ensure that libtrash is started prior to mounting.

NOTE: this assumes you are using openssh-server.

Create a script in nano with the following text in the following location:

• $ sudo nano /usr/lib/openssh/libtrash-sftp-server

In nano, enter the following code and then save the file:

1. #!/bin/bash
2. export LD_PRELOAD=/usr/lib/libtrash/libtrash.so.2.4
3. /usr/lib/openssh/sftp-server

Change permissions to make it executable:

• sudo chmod +x /usr/lib/openssh/libtrash-sftp-server

Then open the configuration file for ssh and make the following change near the very end of the file (comment out the original and add your own):

• $ sudo nano /etc/ssh/sshd_config

73. [ ... ]
75. #Subsystem sftp /usr/lib/openssh/sftp-server
76. Subsystem sftp /usr/lib/openssh/libtrash-sftp-server
78. UsePAM yes

Restart your ssh server and then, when you connect via sshFS (in Ubuntu go to Places < Connect to Server and choose a SFTP (SSH) server; on the Mac, you will need MacFuse and SSHFS) you'll be using your ~/Trash folder.

• $ sudo /etc/init.d/ssh restart

using libtrash with AFP (netatalk)

We need to edit one file in a really strange place in order for this to work. You probably could make a backup copy, if you are afraid of messing something up.

• $ sudo nano /etc/init.d/netatalk

In the middle of this file, you should find this patch of code; insert the highlighted text where it lies:

62. case "$1" in
63.   start)
64.     export LD_PRELOAD=/usr/lib/libtrash/libtrash.so.2.4
65.     if test "x${ATALK_BGROUND}" = "xyes"; then
66.       echo "Starting AppleTalk services in the background."
67.       atalk_startup >/dev/null &
68.     else
69.       echo -n "Starting AppleTalk services (this will take a while): "
70.       atalk_startup
71.       echo "."
72.     fi
73.   ;;

After, simply restart netatalk. You may always want to look at how to securely authenticate your user's login with netatalk as well.

• $ sudo /etc/init.d/netatalk restart

how to empty the trash automatically

If you look in /usr/share/doc/libtrash you will find a lot of interesting information as well as some examples. In the examples directory there are scripts for cleaning your trash can (/usr/share/doc/libtrash/examples/cleanTrash/). I like strash the best. If you do this, you can extract the script, install it to a usable path, and setup the man file (so you can read about its cleverness).

• $ mkdir -p ~/src
• $ cd ~/src
• $ cp /usr/share/doc/libtrash/examples/cleanTrash/strash-0.9.tar.gz ~/src/strash.tar.gz
• $ tar -xvf strash.tar.gz
• $ sudo cp ~/src/strash-0.9/strash /usr/sbin/strash
• $ sudo cp ~/src/strash-0.9/strash.8 /usr/share/man/man8/strash.8

You can read the man page for strash now, which will show you all the nifty options. I added a line to my root crontab (by running: sudo crontab -e) that deletes all files over one month old and will remove files (oldest first) when the total size of the ~/Trash folder is greater than 5GB:

1. # m h dom mon dow command
2. 30 01 * * * /usr/sbin/strash --age 1M --size 5G

Seems to work well. Enjoy.

This entry was posted on Sunday, April 22nd, 2007 at 8:13 am and is filed under how to. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site. Tags: linux, mac, nas, server, trash.