Creating encrypted swap on Ubuntu 14.04 LTS

Turbocapitalist · 11-08-2016, 02:32 AM

I've tried to rearrange swap partitions on Ubuntu 14.04 LTS. Ostensibly I have created two separate encrypted swap partitions. However, they do not survive either hibernation or rebooting. I see that the required devices have disappeared:

Code:

$ sudo swapon -a
swapon: /dev/mapper/cryptswap1: stat failed: No such file or directory
swapon: /dev/mapper/cryptswap2: stat failed: No such file or directory

I can create them manually, but again they don't even survive hibernation, which is where I really need them. What should I be looking at to make the repair?

I've entries for swap in /etc/fstab by UUID or device name, but neither take.

I've entries in /etc/cryptab which refer to the right UUIDs:

Code:

cryptswap1 UUID=72292bd6-d8b8-4952-af17-b2c2af23284e /dev/urandom swap,cipher=aes-cbc-essiv:sha256
cryptswap2 UUID=cd9189b5-e44b-40a2-8d94-9a8d03326da3 /dev/urandom swap,cipher=aes-cbc-essiv:sha256

It seems that the system is not making the devices /dev/mapper/cryptswap1 and /dev/mapper/cryptswap2

cepheus11 · 11-08-2016, 03:37 AM

What is the output of

Code:

blkid

?

Turbocapitalist · 11-08-2016, 03:42 AM

The swap partitions, /dev/sda2 and /dev/sdb2, are not found apparently:

Code:

$ sudo blkid
/dev/sda1: UUID="1ed37aeb-20fe-10ed-f0a3-14554e7b37cc" UUID_SUB="f5f62732-59bf-0fa9-6fd0-ed63da2d3a22" LABEL="gazelle9:0" TYPE="linux_raid_member" 
/dev/sda3: UUID="2b8b9b55-a9c6-4427-9bd2-52a67dd649c6" UUID_SUB="674aa4f5-0ca8-48cf-aa3b-19884c565cf1" LABEL="gazp9:129" TYPE="linux_raid_member" 
/dev/sdb1: UUID="1ed37aeb-20fe-10ed-f0a3-14554e7b37cc" UUID_SUB="c2ffc9f1-1564-3b24-19ad-9a2a7ddf11d1" LABEL="gazelle9:0" TYPE="linux_raid_member" 
/dev/sdb3: UUID="2b8b9b55-a9c6-4427-9bd2-52a67dd649c6" UUID_SUB="805ef6cc-15bd-e61e-1c3d-a97bc9455065" LABEL="gazp9:129" TYPE="linux_raid_member" 
/dev/md0: UUID="427c17e1-3d02-4a3f-9730-4ed54992bddd" TYPE="ext4" 
/dev/md129: UUID="5e8a9dc2-35b3-429c-90f0-3250d9eb63b8" TYPE="ext4"

cepheus11 · 11-08-2016, 04:35 AM

Quote:

Originally Posted by Turbocapitalist

The swap partitions, /dev/sda2 and /dev/sdb2, are not found apparently:

Well, I did not expect them to have a UUID, because UUID is a filesystem property and swap filesystems get created at every reboot after the encryption is set up. But I did expect the partitions to appear in the blkid output and to have a PARTUUID. I don't know why they are not there. Can you see them in (g)parted or another partition manager?

Turbocapitalist · 11-08-2016, 04:37 AM

Yes, they are both listed as "unkown". I can reformat them as swap, start swapping manually but they don't last through the first reboot or hibernation.

syg00 · 11-08-2016, 04:31 PM

caveat: non_Ubuntu, non encrypted swap user.

Sounds like a train wreck looking for a place to happen.
If you want persistence across restarts (i.e. hibernation) why are you using a random key ?.
If you want luks containers re-opened on startup, you'll need the appropriate hooks in your initrd/initramfs - and in the correct order. For separate swap partitions you might need a custom hook as crypttab might not be available at resume.
What does your grub resume parameter(s) look like ?.

(use "lsblk -f" rather than blkid)

Turbocapitalist · 11-08-2016, 09:57 PM

Quote:

Originally Posted by syg00

caveat: non_Ubuntu, non encrypted swap user.

Sounds like a train wreck looking for a place to happen.
If you want persistence across restarts (i.e. hibernation) why are you using a random key ?.
If you want luks containers re-opened on startup, you'll need the appropriate hooks in your initrd/initramfs - and in the correct order. For separate swap partitions you might need a custom hook as crypttab might not be available at resume.
What does your grub resume parameter(s) look like ?.

(use "lsblk -f" rather than blkid)

No. I do not want the contents of swap to persist across reboots. I want the existence of the swap partitions so that the machine may hibernate and wake normally.

The devices seem to disappear some time during either the reboot or, worse, during what should be a normal sleep / wake cycle. Currently, when I close the lid, it gives all appearances of going into hibernation but then when I open the lid, it powercycles itself. Either way, the swap devices themselves are missing from /dev/mapper/

Edit: See the output from swapon -a shown in the earlier post.