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I'm dual-booting Ubuntu 13.10 on an ASUS Windows 8 with an SSD (but not on the SSD).

I configured it when installing to use a swap drive, but it doesn't seem to be using it since I get this message on the load screen:

could not mount /dev/mapper/cryptswap1 M for manual S for skip

And my linux OS keeps crashing.

Here's my question:

I can see two different UUID's for my swap drive:

one from sudo blkid | grep swap:

/dev/mapper/cryptswap1: UUID="a08247f7-a5d9-4d5a-bde7-41339a41ed42" TYPE="swap"

and one from sudo nano /etc/fstab:

# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda8 during installation
UUID=1507d33a-9aed-4091-8d5f-b0d27434f9fc /               ext4    errors=remoun$
# /boot/efi was on /dev/sda1 during installation
UUID=C61B-97CB  /boot/efi       vfat    defaults        0       1
# swap was on /dev/sda9 during installation
# UUID=375639c1-f7b0-4428-a47f-7fdae8f899eb none            swap    sw           $
/dev/mapper/cryptswap1 none swap sw 0 0

I'm wondering should I change the UUID in fstab to the one that I get from blkid? Also, I can see the same UUID when I search ls -l /dev/disk/by-uuid/.

Would it be a problem for me to try changing the swap UUID in fstab (and uncomment), or am I wrong in assuming that I should, or is there a more proper way to fix this problem?

Output of free

             total       used       free     shared    buffers     cached
Mem:       5995912    5030668     965244          0      15588    1169388
-/+ buffers/cache:    3845692    2150220
Swap:      8000508     124356    7876152
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tip, to see if you're using swap, use the free command, it will show a "Swap" line, if that shows 0 then indeed it's not being used. –  roadmr Feb 27 at 21:45
    
@roadmr Updated with output from free. Doesn't appear to be 0. But why would it be commented out in /etc/fstab? –  bozdoz Feb 27 at 21:47

1 Answer 1

# swap was on /dev/sda9 during installation
# UUID=375639c1-f7b0-4428-a47f-7fdae8f899eb none            swap    sw           $
/dev/mapper/cryptswap1 none swap sw 0 0

My guess is that initially swap is created here, but then the partition gets formatted as cryptswap, so instead of using the raw partition and the UUID, it relies on /dev/mapper (which is why the UUID line is commented out).

For reference, on my system the UUIDs are also different, but cryptswap1 is correctly mounted.

cryptswap is configured in /etc/crypttab, should contain something like this for your system (note that fstab says that your swap was originally on /dev/sda9):

cryptswap1 /dev/sda9 /dev/urandom swap,cipher=aes-cbc-essiv:sha256

If the partitions have been relocated somehow and /dev/sda9 no longer exists, you probably need to update crypttab to reflect the new location.

You can find more information on how to set up and diagnose cryptswaps here:

http://hydra.geht.net/tino/howto/linux/cryptswap/

share|improve this answer
    
My /etc/cryptab says the same thing. Do you get the could not mount message on the load screen? @roadmr –  bozdoz Mar 1 at 1:57
    
Hi! no, sorry, my crypttab mounts correctly :( so I'm not entirely sure what could be wrong with yours. –  roadmr Mar 3 at 15:48

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