Tag Archives: ubuntu

Adding a LUKS-encrypted iSCSI volume to Synology DS414 NAS and Ubuntu 15.04

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I have an Ubuntu 15.04 “Vivid” workstation already set up with LUKS full disk encryption, and I have a Synology DS414 NAS with 12TB raw storage on my home network. I wanted to add a disk volume on the Synology DS414 that I could mount on the Ubuntu server, but NFS doesn’t support “at rest” encrypted file systems, and using EncFS over NFS seemed like the wrong way to go about it, so I decided to try setting up an iSCSI volume and encrypting it with LUKS. Using this type of setup, all data is encrypted both “on the wire” and “at rest”.

Log into the Synology Admin Panel and select Main Menu > Storage Manager:

  • Add an iSCSI LUN
    • Set Thin Provisioning = No
    • Advanced LUN Features = No
    • Make the volume as big as you need
  • Add an iSCSI Target
    • Use CHAP authentication
    • Write down the login name and password you choose

On your Ubuntu box switch over to a root prompt:

sudo /bin/bash

Install the open-iscsi drivers. (Since I’m already running LUKS on my Ubuntu box I don’t need to install LUKS.)

apt-get install open-iscsi

Edit the conf file

vi /etc/iscsi/iscsid.conf

Edit these lines:

node.startup = automatic
node.session.auth.username = [CHAP user name on Synology box]
node.session.auth.password = [CHAP password on Synology box]

Restart the open-iscsi service:

service open-iscsi restart
service open-iscsi status

Start open-iscsi at boot time:

systemctl enable open-iscsi

Now find the name of the iSCSI target on the Synology box:

iscsiadm -m discovery -t st -p $SYNOLOGY_IP
iscsiadm -m node

The target name should look something like “iqn.2000-01.com.synology:boxname.target-1.62332311”

Still on the Ubuntu workstation, log into the iSCSI target:

iscsiadm -m node --targetname "$TARGET_NAME" --portal "$SYNOLOGY_IP:3260" --login

Look for new devices:

fdisk -l

At this point fdisk should show you a new block device which is the iSCSI disk volume on the Synology box. In my case it was /dev/sdd.

Partition the device. I made one big /dev/sdd1 partition, type 8e (Linux LVM):

fdisk /dev/sdd

Set up the device as a LUKS-encrypted device:

cryptsetup --verbose --verify-passphrase luksFormat /dev/sdd1

Open the LUKS volume:

cryptsetup luksOpen /dev/sdd1 backupiscsi

Create a physical volume from the LUKS volume:

pvcreate /dev/mapper/backupiscsi

Add that to a new volume group:

vgcreate ibackup /dev/mapper/backupiscsi

Create a logical volume within the volume group:

lvcreate -L 1800GB -n backupvol /dev/ibackup

Put a file system on the logical volume:

mkfs.ext4 /dev/ibackup/backupvol

Add the logical volume to /etc/fstab to mount it on startup:

# Synology iSCSI target LUN-1
/dev/ibackup/backupvol /mnt/backup ext4 defaults,nofail,nobootwait 0 6

Get the UUID of the iSCSI drive:

ls -l /dev/disk/by-uuid | grep sdd1

Add the UUID to /etc/crypttab to be automatically prompted for the decrypt passphrase when you boot up Ubuntu:

backupiscsi UUID=693568ca-9334-4c19-8b01-881f2247ae0d none luks

If you found this interesting, you might want to check out my article Adding an external encrypted drive with LVM to Ubuntu Linux.

Hope you found this useful.

Click to stream .m3u files in Ubuntu

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I just recently heard about CCMixter.org on FLOSS Weekly. CCMixter.org is a resource and collaborative space for musicians and remixers. They have thousands of music tracks which can be downloaded, remixed, sampled, or streamed.

I recently did a fresh install of Ubuntu on the computer I was using, and clicking on any of CCMixter’s streaming links caused a window to pop up asking me if I wanted to play the stream using Rhythmbox or “Other”. Selecting Rhythmbox popped up Rhythmbox, but it wouldn’t play the stream. Googling around a bit led me to discussions of Rhythmbox brokenness going back to 2008, so I took a different tack.

I fired up Synaptic Package Manager and installed the VLC Media Player.

Then I clicked the gear icon on Unity’s upper right menu bar, selected “About this Computer”, clicked Default Applications, and changed the default application for Music to “VLC Media Player.”

Now when I click on a link to an .m3u stream, Ubuntu sends the link to VLC, and the music starts to play.

Hope you find this useful.

Bring Pidgin’s window into front focus when there’s an inbound IM

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I was talking to a co-worker about Pidgin not coming into focus when there’s a new, inbound IM. The Pidgin window used to come into focus, front and center, when I was running Ubuntu/Gnome and when running OpenSUSE/KDE, but when I upgraded my office desktop to Ubuntu/Unity it stopped behaving this way. My co-worker noticed the same behavior with Fedora17/Gnome. A new IM would come in, but the Pidgin IM window would remain in the background, hidden, unseen and unread.

I thought “There has to be a setting that controls this,” and there is…

  • Bring up Pidgin’s Buddy List
  • Click Tools > Plugins
  • Locate the Message Notification plugin and highlight it
  • At the bottom of the Plugins window is a Configure Plugin button. Click it
  • Under Notification Methods check both Raise conversation window and Present conversation window
  • Click Close

That’s it. The next time someone IM’s you, your Pidgin Conversation will pop up in the center of your screen, in front of all of your other windows.

Hope you find this useful.

Getting rid of self-resizing windows in Ubuntu Linux 12.04

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I’ve been using a pre-release “daily build” installation of Ubuntu 12.04 “Precise Pangolin” and noticed that current default for Gnome is for windows to resize themselves when you get close to the edge of the screen. I have two 22″ widescreen monitors and if I moved a window near the top edge it would maximize and fill the screen. If I moved a window to any edge Gnome would decide for me that what I “really” wanted was to enlarge the window to fill half the screen or do something else equally annoying. This might work well on a 10″ netbook screen, but on dual 22″ monitors it’s annoying as hell.

I tracked the problem down to a setting in Compiz, the screen compositing tool used by many Linux desktop environments, so if you’re using KDE or Unity with Compiz and you’re finding self-resizing windows irritating this fix should work for you as well.

To fix the problem you need to install the CompizConfig Settings Manager, so fire up Synaptic Package Manager and search for “compizconfig-settings-manager” and install it.

Once installed, if you’re using Gnome go to Applications > System Tools > Preferences and click “CompizConfig Settings Manager” to start the tool.

Scroll down to “Window Management.”

Uncheck “Place Windows”.

Leave “Grid” checked, but click the word “Grid” to get the Grid settings, then go to the Edges tab and change all Resize Actions to “None”.

Click Back.

Now your desktop will do what you tell it to do, rather than second-guessing you and doing something that you do not want.

One thing that you can now do (that you probably really don’t want) is to have the title bar (and it’s controls) move off-screen, which means you can’t move or resize the window unless you Alt-right-click on it. To fix that issue:

Check the “Put” plugin.

Click the word “Put” to bring up more options, go to the “Misc Options” tab, check “Avoid Offscreen”, click Back, then Close Window.

Hope you find this useful.

Work-around for a locked-up Gnome 3 screen saver in Ubuntu 11.10

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Gnome 3 has a screen saver (or more accurately a screen blanker — there are no pretty pictures) which is turned on by default and which password-protects (locks) your desktop by default when it activates. Unfortunately it’s been known to be buggy since it was released as part of Gnome 2, often refusing to unlock your screen and forcing you to reboot your system.

Users of the Gnome 3 desktop shell are reporting that for some video card and monitor combinations the Gnome 3 screen saver, after getting a key press / mouse movement that should prompt you for your password to unlock the screen:

  • Won’t unlock the screen at all.
  • Will display a mouse pointer but no password prompt.
  • Will display your original screen and all open documents (without prompting for a password) but will not allow you to click on anything, basically appearing as a locked-up desktop.

My setup reliably produces situation #3.

To unlock a locked-up desktop:

  • Ctrl-Alt-F1 will give you a text-based terminal login.
  • Log in with your user name and password.
  • Type: “killall gnome-screensaver”
  • Ctrl-Alt-F7 to get back to the (now unlocked) Gnome 3 desktop.

To replace the Gnome 3 screen saver with something less buggy:

  • Activities > Applications > Other > Synaptic Package Manager
  • Quick filter: xscreensaver
  • Right click ‘xscreensaver’ and select ‘Mark for Installation’
  • Click ‘Apply’ to install
  • Activities > Applications > System Tools  > System Settings > Screen
  • Set “Turn off after” to ‘Never’ and “Lock” to ‘OFF’. This disables gnome-screensaver.
  • Activities > Applications > All > Screensaver
  • Follow the prompts to activate xscreensaver

If you try to uninstall gnome-screensaver Synaptic Package Manager will also want to uninstall gnome and gnome-core, which is a bad idea if you want to run Gnome. Gnome will always start gnome-screensaver even if you have it disabled, and xscreensaver won’t run if gnome-screensaver is running. So you basically need to kill gnome-screensaver after Gnome has started and then start xscreensaver. You can do this by adding a startup program:

  • Activities > Applications > Other > Startup Programs > Add
  • Name: “Screen Saver”
  • Command: “sleep 30; killall gnome-screensaver; sleep 5; xscreensaver”
  • Comment: “Kill gnome-screensaver, start xscreensaver”
  • Click “Add”

Hope you find this useful.