Thomas Bächler wrote: > We have encountered a problem with blkid that is caused by cryptsetup > not cleaning superblocks of old filesystems on luksFormat. The problem > has been fixed in 1.0.7, however old LUKS volumes still suffer from this > problem. Please read this thread for details: > > http://thread.gmane.org/gmane.linux.utilities.util-linux-ng/2563 > > What I would request is an option to "clean" the unused area in the LUKS > header up to the start of the payload, such that for example an old ext2 > magic is removed. All that without destroying the used areas in the LUKS > header, of course. > > I'm not very familiar with the LUKS code or on-disk format, so I would > be greatful if anyone who is would implement such a feature. Thanks for > your replies. Hi Thomas, I don't think we need implement any clean function, new version already wipes that area. Because visible LUKS header is written in first 2 sectors and keyslot area always begins on 4k offset, you can use this command to wipe unused area with possible old signature (at least this works for swap/luks signature mismatch): dd if=/dev/zero of=<device> bs=512 seek=2 count=6 But please create backup before trying this... ;-) (btw mkswap should clean LUKS signature too - try mkswap over old LUKS and then blkid:-) Milan -- mbroz@xxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe util-linux-ng" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
