UUID anomaly

Nils Kassube kassube at gmx.net
Fri Jul 9 11:14:31 UTC 2010

Markus Schönhaber wrote:
> > Nils Kassube wrote:
> >> I suppose you used "blkid" and not "sudo blkid". Calling blkid
> >> without sudo doesn't necessarily tell you the current state but
> >> the one from the cache file /etc/blkid.tab which was written when
> >> blkid was last used with sudo.
> That's interesting, indeed.
> I've never fallen into this trap since I wasn't aware that blkid uses
> a cache file. Therefore, for me, running blkid was associated with
> "must access raw device" and in turn "needs root privileges".

The behaviour of blkid changed about a year ago and I remember a 
discussion about it (I think on this list). Previously there was no 
output for unprivileged users. But after the change, the output came 
from the cache file. Nowadays I avoid the blkid command and use

ls -l /dev/disk/by-*/

instead. I'm quite confident that the output of this command is real and 
not from a cache file.


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