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

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 “”

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.

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Peerio promises privacy for everyone

A new company called Peerio is promising secure, easy messaging and file sharing for everyone. They’re building apps that encrypt everything you send or share, making the code for these apps open source, and paying for security audits to peer-review the source code, looking for security weaknesses.

They’ve put together a short video to explain the basics of what they offer. I thought I’d give it a try and see how it works.

I went to using the Chrome browser, so the home page automatically offered to install Peerio on Chrome.

I clicked the install button and Peerio popped up as a new Chrome app.


Clicking the app brought up the new account screen, with the word “beta” displayed in small type just under the company logo, so they’re letting me know up front that this is going to be a little rough.


I clicked Sign Up, added a user name and email address, and was prompted for a pass phrase.

I have a couple of pass phrases I use. I typed one in, but apparently it wasn’t long enough. I tried another and another. Not long enough. The words “ALMOST THERE. JUST A FEW MORE LETTERS…” appeared on screen. One phrase I typed in had 40+ letters in it, but still the words “ALMOST THERE. JUST A FEW MORE LETTERS…” persisted. Tried again, this time putting spaces between the words. Phrase accepted! Maybe the check is trying to verify the number of space-separated words, not the total number of characters? Anyhow, got past that hurdle.

Next it sends you an email with a confirmation code and gives you 10 minutes (with a second by second countdown) to enter the confirmation code. I guess if you don’t enter it within 10 minutes your account is toast?

Once past that step I was prompted to create a shorter PIN code that can be used to login to the site. The long pass phrase is only needed to log in the first time you use a new device, after that your PIN can be used. I tried entering a few short number sequences. All were rejected as “too weak” so I used a strong, unique password with a mix of upper and lowercase letters, numbers, and special characters. The screen hid what I was typing and only asked for the PIN once, so if I thumb-fingered it, my account was going to be rendered useless pretty quickly. Hopefully I typed what I thought I typed.


Of course to use the service to send messages to people you have to load your contacts in. I added a friend’s email and Peerio sent him an invite. Tried adding another email address and the “Add Contact” form cut me off at the “.c” in “.com” — looks like the folks at Peerio only let you have friends with email addresses that are less than 16 characters long. My friends at, you’re out of luck.


The Contacts tab has sub-tabs for “All Contacts”, “Confirmed Contacts”, and “Pending Contacts”, but the one email address I entered that was less than 16 characters long didn’t show up anywhere (I expected to see it under “Pending Contacts”). With my entries disappearing or truncated, I stopped trying to use the system.

It’s an interesting idea for a service, the source code for the clients is supposed to be available on Github, but the site directed me to for the source, and that link is 404. Searching Github for “Peerio” shows and, so it looks like this is just a case of a BETA web site with a broken link.

Before the developers pay for another security audit, they really ought to try doing some basic usability testing — set up a new user in front of a laptop, and make two videos — one of the keyboard and screen and one of the user’s face, and then watch them try to log in and set up an account. I think they’d find the experience invaluable.

Anyhow, if you’re interested and feel like trying out their very BETA (feels like ALPHA) release, head over to and sign up. If you want to send me a message, you can reach me on Peerio as “earl”.

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Adding an external encrypted drive with LVM to Ubuntu Linux

I recently added an external eSATA drive to my home computer so I could back up critical data from my home network to one drive. I bought a Western Digital 1TB “green” drive and a Thermaltake external hard drive enclosure with eSATA and USB connectors.

Since my internal hard drives are encrypted it didn’t make sense to back up all of that data to an unencrypted external drive. I’d read Uwe Hermann’s excellent how-to article on disk encryption, but he didn’t cover setting up an LVM partition, which I always use so I can change drive volume sizes on the fly.

This is what I did to set up an external encrypted drive with LVM on an Ubuntu system:

  1. Open a terminal
  2. Get a root prompt:
    sudo /bin/bash
  3. Watch the system log:
    tail -f /var/log/messages
  4. Attach the external drive. The system log tells me that it was detected as /dev/sdc.
  5. Check the drive for bad blocks (takes a couple of hours):
    badblocks -c 10240 -s -w -t random -v /dev/sdc
  6. Write random data to the entire drive. This step takes all night, but it ensures that never-written drive space can’t be differentiated from encrypted data if someone ever tries to crack the drive. (If you’re going to do this, you might as well do it right.)
    shred -v -n 1 /dev/sdc
  7. Create one big LVM partition on the drive using fdisk. Set up one big primary partition /dev/sdc1, set the tag to system id “8e” LVM, and write the changes to disk:
    > fdisk /dev/sdc                                                                                                                                              
    Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel                                                                                                  
    Building a new DOS disklabel with disk identifier 0xa6846916.                                                                                                                       
    Changes will remain in memory only, until you decide to write them.                                                                                                                 
    After that, of course, the previous content won't be recoverable.                                                                                                                   
    The number of cylinders for this disk is set to 121575.
    There is nothing wrong with that, but this is larger than 1024,
    and could in certain setups cause problems with:               
    1) software that runs at boot time (e.g., old versions of LILO)
    2) booting and partitioning software from other OSs                                                                                                                                 
       (e.g., DOS FDISK, OS/2 FDISK)                                                                                                                                                    
    Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)                                                                                                      
    Command (m for help): p                                                                                                                                            
    Disk /dev/sdc: 999.9 GB, 999989182464 bytes                                                                                                                                         
    255 heads, 63 sectors/track, 121575 cylinders                                                                                                                                       
    Units = cylinders of 16065 * 512 = 8225280 bytes                                                                                                                                    
    Disk identifier: 0xa6846916                                                                                                                                                         
       Device Boot      Start         End      Blocks   Id  System                                                                                                                      
    Command (m for help): n                                                                                                                                            
    Command action                                                                                                                                                                      
       e   extended                                                                                                                                                                     
       p   primary partition (1-4)                                                                                                                                                      
    Partition number (1-4): 1                                                                                                                                          
    First cylinder (1-121575, default 1): [ENTER]                                                                                                                      
    Using default value 1
    Last cylinder, +cylinders or +size{K,M,G} (1-121575, default 121575): [ENTER]
    Using default value 121575
    Command (m for help): t
    Selected partition 1
    Hex code (type L to list codes): 8e
    Changed system type of partition 1 to 8e (Linux LVM)
    Command (m for help): p
    Disk /dev/sdc: 999.9 GB, 999989182464 bytes
    255 heads, 63 sectors/track, 121575 cylinders
    Units = cylinders of 16065 * 512 = 8225280 bytes
    Disk identifier: 0xa6846916
       Device Boot      Start         End      Blocks   Id  System
    /dev/sdc1               1      121575   976551156   8e  Linux LVM
    Command (m for help): w
    The partition table has been altered!
    Calling ioctl() to re-read partition table.
    Syncing disks.
  8. Use cryptsetup to encrypt the drive:
    cryptsetup --verbose --verify-passphrase luksFormat /dev/sdc1
  9. Unlock the drive:
    cryptsetup luksOpen /dev/sdc1 backupexternal
  10. Create the LVM physical volume:
    pvcreate /dev/mapper/backupexternal
  11. Create the LVM volume group:
    vgcreate xbackup /dev/mapper/backupexternal
  12. Create a logical volume within the volume group:
    lvcreate -L 500G -n backupvol /dev/xbackup
  13. At this point you have a device named /dev/xbackup/backupvol, so create a filesystem on the logical volume:
    mkfs.ext4 /dev/xbackup/backupvol
  14. Mount the volume:
    mount /dev/xbackup/backupvol /mnt/backup
  15. To get the volume to mount automatically at boot time add this line to your /etc/fstab file:
    /dev/xbackup/backupvol      /mnt/backup     ext4    defaults        0 5
  16. To be prompted for the decryption key / passphrase at boot time first get the drive’s UUID:
    ls -l /dev/disk/by-uuid

    (In my example I use the UUID for /dev/sdc1)

  17. Then add this line to the /etc/crypttab file:
    backupexternal UUID=[the UUID of the drive] none luks

That’s it. You now have an external, encrypted hard drive with LVM installed. You’ve created one 500GB volume that uses half the disk, leaving 500GB free for other volumes, or for expanding the first volume.

Hope you find this useful.

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