Swap UUID does not show up in blkid etc.!!??

[Piraja]

Hey, I know I caused my swap UUID to change since I messed about with an external disk installation (I'm not going into details now, but trying to install Debian Etch on an external USB HDD turned out to be trickier than I thought; the thing is that the Debian "expert mode" installer insists on using the internal HDD's swap space and does not even offer an alternative or ask me about this detail...).

And I know from experience (I've encountered this before) that I must edit fstab. However, this blkid output puzzles me:

/dev/sda1: UUID="0B92DAEF522D1731" TYPE="ntfs" 
/dev/sda2: LABEL="HP_TOOLS" UUID="A438-DD58" TYPE="vfat" 
/dev/sda3: UUID="E056567B56565280" LABEL="HP_RECOVERY" TYPE="ntfs" 
/dev/sda5: UUID="a1e4fde2-dfe2-4d47-9951-f4062b5d6f38" TYPE="ext3" 
/dev/sda6: TYPE="swap" 
/dev/sda7: UUID="74fb6d68-7846-4ecb-97b6-38b65ab5947c" TYPE="ext3" SEC_TYPE="ext2" 
/dev/sdb1: UUID="c08e23c1-aa25-4cad-9692-77f4c553bd0e" TYPE="ext3" 
/dev/sdb3: UUID="2bc32022-27a8-47d5-8d33-83c86e23618c" TYPE="ext3" 
/dev/sdb5: TYPE="swap"

Firstly, I don't have an external USB drive plugged in at the moment (showing as sdb). Secondly, why does it say just "swap" without UUID?

Well, the next thing to do might be simply typing man blkid...

... and figuring out I should maybe try this: sudo blkid -c /dev/null

/dev/sda1: UUID="0B92DAEF522D1731" TYPE="ntfs" 
/dev/sda2: LABEL="HP_TOOLS" UUID="A438-DD58" TYPE="vfat" 
/dev/sda3: UUID="E056567B56565280" LABEL="HP_RECOVERY" TYPE="ntfs" 
/dev/sda5: UUID="a1e4fde2-dfe2-4d47-9951-f4062b5d6f38" TYPE="ext3" 
/dev/sda6: TYPE="swap" 
/dev/sda7: UUID="74fb6d68-7846-4ecb-97b6-38b65ab5947c" TYPE="ext3"

Still no UUID for swap. I don't get it.

[Piraja]

See also this:

piraja@berserkerberos:~$ ls -l /dev/disk/by-uuid/
total 0
lrwxrwxrwx 1 root root 10 2009-01-15 21:40 0B92DAEF522D1731 -> ../../sda1
lrwxrwxrwx 1 root root 10 2009-01-15 23:37 74fb6d68-7846-4ecb-97b6-38b65ab5947c -> ../../sda7
lrwxrwxrwx 1 root root 10 2009-01-15 23:37 a1e4fde2-dfe2-4d47-9951-f4062b5d6f38 -> ../../sda5
lrwxrwxrwx 1 root root 10 2009-01-15 21:40 A438-DD58 -> ../../sda2
lrwxrwxrwx 1 root root 10 2009-01-15 21:40 E056567B56565280 -> ../../sda3

The swap partition (sda6) is not listed, as you see.

I did "swapon" and I have to do it at each boot, after which the usual "0 %" indeed shows up in Conky.

[Piraja]

... and this:

piraja@berserkerberos:~$ sudo vol_id /dev/sda6
[sudo] password for piraja: 
ID_FS_USAGE=other
ID_FS_TYPE=swap
ID_FS_VERSION=2
ID_FS_UUID=
ID_FS_UUID_ENC=
ID_FS_LABEL=
ID_FS_LABEL_ENC=
ID_FS_LABEL_SAFE=
piraja@berserkerberos:~$

[Piraja]

Well, here comes a workaround. I found it here at UF, having already figured out that I could possibly just remove the wrong UUID from fstab, searching by the terms "swap remove wrong uuid fstab". I replaced the wrong UUID with the device path, as follows:

/dev/sda6 none            swap    sw              0       0

I don't really like this solution, or rather workaround, because I believe it is generally a good idea to have devices pointed at in fstab by UUIDs instead of other possible alternatives (i.e. dev path, label).

[Yashiro]

Try swapoff, reformatting the partition and setting swapon using gparted and not any other tools.

Or generate a new UUID for the swap, maybe.
http://pwet.fr/man/linux/commandes/uuidgen

[caljohnsmith]

Oops, didn't see Yashiro's post where he says the same thing I was going to say.

[Piraja]

Thank you Yashiro and caljohnsmith!

I used the Gparted method, did sudo vol_id /dev/sda6, received the new UUID and edited fstab accordingly.

Such posts make the present absence of the "Thank you" button ever more conspicuous.

(Hmmm... Also "Mark this thread as 'Solved'" has disappeared...?)

[Yashiro]

Send the cheque in the post. Or a Pot Noodle.

[Piraja]

You do have a money-back guarantee policy, don't you?

Seriously speaking, swap still isn't automatically activated at boot, in spite of the fact that the swap UUID shown by blkid is identical with the one in fstab. Well, the difference is indeed that now blkid shows the swap UUID, whereas it previously did not. Yet, it has this funny detail that while all other lines have UUID first, sda6 has "TYPE=swap" before the UUID...

piraja@berserkerberos:~$ sudo blkid -c /dev/null
/dev/sda1: UUID="0B92DAEF522D1731" TYPE="ntfs" 
/dev/sda2: LABEL="HP_TOOLS" UUID="A438-DD58" TYPE="vfat" 
/dev/sda3: UUID="E056567B56565280" LABEL="HP_RECOVERY" TYPE="ntfs" 
/dev/sda5: UUID="a1e4fde2-dfe2-4d47-9951-f4062b5d6f38" TYPE="ext3" 
/dev/sda6: TYPE="swap" UUID="c1c7221c-8ea1-4ea6-b47f-ffb829194ae0" 
/dev/sda7: UUID="74fb6d68-7846-4ecb-97b6-38b65ab5947c" TYPE="ext3" 
piraja@berserkerberos:~$

Strange!!??

[caljohnsmith]

That does seem strange that blkid would list the type before the UUID; I've never seen that before, so I don't know if that is OK or a sign that something is wrong. Considering that you are still having problems using your swap though, I'm inclined to think it's a sign something is not quite right. Also, have you lost your Ubuntu splash screen on start up? That's also usually a symptom of having problems with the swap partition. How about doing:

cat /etc/initramfs-tools/conf.d/resume

If that file shows a UUID which should be for your swap partition, then how about trying:

sudo swapoff -a
sudo mkswap -U $(awk -F"=" '{print $3}' /etc/initramfs-tools/conf.d/resume) /dev/sda6

Also, modify your fstab to use the UUID for the swap partition shown in the resume file above, then reboot and post the output of:

sudo fdisk -lu
sudo blkid -c /dev/null
cat /etc/fstab
cat /etc/initramfs-tools/conf.d/resume
free

And we can work from there if you want.