I run Ubuntu 16.04 on my Dell XPS 13 9350 (not the Developer Edition). Everything mostly just works, but I have run into some annoying problems relating to home drive encryption. I first experienced them in Ubuntu 15.10; unfortunately, they were not (yet) fixed in 16.04 either.
Disk Encryption Password Prompt
When I would boot, I would be greeted with the following message:
"Please enter passphrase for disk (cryptswap1) on none"
Being relatively new to Ubuntu, I thought this was normal behavior and I needed to enter my password to decrypt my home drive (I had elected to encrypt my home drive during installation).
I dutifully entered my password each time I booted; however, once I accidentally pressed the enter key before I entered my password. To my surprise, Ubuntu accepted this and booted normally. After some research on the topic, it turns out this is a known issue, which will hopefully be fixed soon. There is a workaround, but with a fix on the way, I decided to live with the extra keystroke.
While the password prompt was mildly annoying, it was pretty easy to just skip past it. The second problem (or really set of problems) I discovered was more frustrating as it affected a fairly typical workflow: shutdown and reboot.
I began to notice the Ubuntu UI options to reboot or shutdown my laptop would stop working; i.e. nothing would happen when selected. Eventually I realized this would only occur if I had previously suspended my laptop. If I booted from a powered off state and rebooted or shut down with no suspend in between, everything worked fine.
My first attempt at a solution was to shutdown using the terminal; however issuing the command
would result in the following error message:
Failed to start poweroff.target: Transaction is destructive.
That didn’t sound good. And now I couldn’t power off, either. The only way I could actually power off my laptop (other than holding down the power button) was to run
sudo poweroff -f
Turns out this is another known issue; the steps to reproduce match mine almost exactly. But it gets worse: the issue has a status of “Won’t Fix”.
For a while, I accepted my lot in life and issued the force shutdown command from the terminal whenever I wanted to power off.
But I started to wonder, “What if the two problems are somehow related?” I decided to take a stab at implementing the workaround mentioned above. Yes, it does make the system less secure overall. But it is reversible, and if it fixed my shutdown/power off problems, I was willing to accept that until (hopefully) a permanent fix is released.
Since the workaround involves modifying partitions, I first backed up my home drive to an external hard drive. Next, I followed all the steps as described in the link above:
1) Find the partition that has the swap
sudo fdisk -l Disk /dev/sda: 233,8 GiB, 251000193024 bytes, 490234752 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: gpt Disk identifier: B59D4149-AC8E-4B71-B51F-8926B2E82C14 Device Start End Sectors Size Type /dev/sda1 2048 409599 407552 199M EFI System /dev/sda2 409640 253319775 252910136 120,6G Apple HFS/HFS+ /dev/sda3 253321216 269320191 15998976 7,6G Linux swap /dev/sda4 269320192 490233855 220913664 105,3G Linux filesystem
2) Turn off swap
sudo swapoff -a
3) Disable cryptswap (it’s possible this may not exist, that is fine)
sudo cryptsetup remove /dev/mapper/cryptswap1
4) Remove the corresponding line in /etc/crypttab
sudo vim /etc/crypttab
5) Setup new swap area (use swap partition from fdisk output above)
sudo /sbin/mkswap /dev/sda3 sudo swapon /dev/sda3
6) Replace /dev/mapper/cryptswap1 with /dev/sda3 in fstab
sudo vim /etc/fstab
After rebooting, I was no longer prompted to enter a cryptswap password. But even better, I could now reboot and shutdown normally! Apparently, the two issues are related in some way. I’m not smart enough to figure out how, but I’ll take it!