On Mon 07 Nov 2016 at 21:07:45 +0100, Pascal Hambourg wrote: > Le 07/11/2016 à 15:18, Richard Owlett a écrit : > >>> > >>> tomas@rasputin:~$ ls -al /dev/sd* > >>> brw-rw---- 1 root disk 8, 0 Nov 7 09:06 /dev/sda > >>> brw-rw---- 1 root disk 8, 1 Nov 7 09:06 /dev/sda1 > >>> brw-rw---- 1 root disk 8, 2 Nov 7 09:06 /dev/sda2 > >>> brw-rw---- 1 root disk 8, 5 Nov 7 09:06 /dev/sda5 > >>> > >>>So you'd have to be associated to the "disk" group to read those > >>>things and you'd have to *be* root to write. > > > >Evidently not a solution. Added myself to both "disk" and "root" groups. > >Had no effect when attempting to run either lsblk or parted. > > Did you start a new session after adding yourself to the group ? > New groups are only taken into account when opening a session. > FWIW, adding myself to the "disk" group and starting a new session worked > with lsblk -f. Didn't try parted.
Is the suggestion to give a user raw access to disks a serious one? > >Off-list it was suggested I try /sbin/blkid /dev/sda. Although the man > >page has a caution when not used as root, it seems to currently work on > >my immediately available Debian machine. > > Indeed blkid uses a cache file which is readable by everyone and is updated > by udev. A very useful observation. When blkid is run as root it creates the file /run/blkid/blkid.tab. A user running blkid only gets to see the contents of blkid.tab. There is no change to blkid.tab unless the command is run by root again. This makes /sbin/blkid useless as a user command for the purposes discussed in this thread. -- Brian.
