Re: parted is ALMOST suitable

[Greg Wooledge <wooledg@eeg.ccf.org>]

On Mon, Nov 07, 2016 at 03:27:12PM +0100, tomas@tuxteam.de wrote:
> Two things:
>  - check that your disk devices are actually readable (and probably
>    writable, I botched that, cf. David's mail) by group disk
>  - your being added to disk is effective *after* logging in after
>    you'd made the change; if you want to bypass it, there is the
>    command 'newgrp'; you can check which groups you are "in" by
>    issuing the command 'groups': 'disk' should be in there.

I started writing that in my previous message, but then I actually
tested it on my own system.  Good thing I did, because I got the
same result as Richard: being in group disk, which has read/write
access on /dev/sda*, does NOT give you output in the FSTYPE and other
fields of lsblk -f.  It certainly surprised me.

$ sudo adduser wooledg disk
Adding user `wooledg' to group `disk' ...
Adding user wooledg to group disk
Done.

$ su - wooledg -c 'LANG=C; id; lsblk -f'
Password: 
uid=563(wooledg) gid=563(wooledg) groups=563(wooledg),6(disk),24(cdrom),25(floppy),27(sudo),29(audio),30(dip),44(video),46(plugdev),108(netdev)
NAME   FSTYPE LABEL UUID MOUNTPOINT
sda                      
|-sda1                   
|-sda2                   /
`-sda3                   [SWAP]
sr0                      

Whatever lsblk wants in order to read the FSTYPE, I don't know, but
group disk membership is not sufficient.  (On jessie.)

I still suggest just sucking it up and using sudo like a normal person.