Arch Linux

Harey

Member

From: Bavaria, Germany

Registered: 2007-03-24

Posts: 374

luks encrypted swap warning message

Hi there,

I use encrypted partitions on my laptop following the luks wiki:
http://wiki.archlinux.org/index.php/LUKS
I have encrypted swap like mentionend there by the entry of

swap    /dev/mapper/swap    SWAP        -c aes-xts-plain -h whirlpool -s 512

in /etc/crypttab.
This worked fine for some time but now it throws a warning during boot that reads:

Unlocking encrypted volumes...
mkswap:/dev/mapper/swap warning: don't erase bootbit sectors on whole disk, use -f instead

Do I have to be concerned about that?

Harvey

Last edited by Harey (2009-08-03 20:09:16)

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Linux is like a wigwam: No Gates, no Windows and an Apache inside

Rorschach

Member

From: Ankh-Morpork

Registered: 2008-11-07

Posts: 143

Re: luks encrypted swap warning message

This entry in your crypttab doesn't look correct for me.  In the crypttab you have to provide the partition where you want your swapspace. E.g. if its /dev/hda3 the entry in the crypttab should look like:

swap    /dev/hda3    SWAP        -c aes-xts-plain -h whirlpool -s 512

The swap at the beginning of the line is already telling that it goes to /dev/mapper/swap. The second field is the partition and not the mapping folder!

And in the fstab you have to provide:

/dev/mapper/swap swap swap defaults 0 0

greetings

Harey

Member

From: Bavaria, Germany

Registered: 2007-03-24

Posts: 374

Re: luks encrypted swap warning message

/etc/crypttab:
swap    /dev/sdb2    SWAP        -c aes-xts-plain -h whirlpool -s 512

/etc/fstab:
/dev/mapper/swap swap swap defaults 0 0

This is in fact how it looks like. I am writing this on another Computer so I mixed the entries. Sorry about that.

The warning is concerning mkswap using some wrong option while making the swapspace. Seems to have changed in the near past, now throwing this warning. Maybe an update of util-linux-ng package?

Still have no clue why this is so.

Harvey

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Linux is like a wigwam: No Gates, no Windows and an Apache inside

Rorschach

Member

From: Ankh-Morpork

Registered: 2008-11-07

Posts: 143

Re: luks encrypted swap warning message

I'm using an encrypted swap-space on two uptodate-patched archlinux systems so I don't think the problem comes from archlinux.

bender02

Member

From: UK

Registered: 2007-02-04

Posts: 1,328

Re: luks encrypted swap warning message

I get the same message, also using up-to-date arch (testing enabled). Same setup (except instead of /dev/sdb2 I have it on a logical volume /dev/vg/swap). Don't know where it comes from.

Don't be so quick condemning something just because it works on your system.

EDIT: It probably has to do with the updated mkswap (util-linux-ng) package.

Last edited by bender02 (2009-08-03 14:23:31)

Harey

Member

From: Bavaria, Germany

Registered: 2007-03-24

Posts: 374

Re: luks encrypted swap warning message

testing is enabled here also, my system is up-to-date as well. I also think it has to do with updated mkswap from util-linux-ng. 
http://www.kernel.org/pub/linux/utils/u … leaseNotes
My setup has been working for a while without this warning while I did not install anything. I guess pacman -Syu brought this in with the updated util-linux-ng.

Harvey

Last edited by Harey (2009-08-03 20:16:01)

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Linux is like a wigwam: No Gates, no Windows and an Apache inside