Unable to write to new poartitions

[Colin Watson]

On Sat, Mar 17, 2018 at 09:34:16PM +0800, Bret Busby wrote:
> I shrank the boot partitions of teo installed operating systems, and,
> for each thence created unallocated space, I created a new sext4
> partition, to which, I assigned the respective labels Data05 and
> Data06.
> 
> I then, from within my UbuntuMATE 16.04 installation, ran sudo chmod
> 777 on each new partition, so as to enable read+write access to the
> two partitions.
> 
> But, I can not write to the two partitions.
> 
> What do I need to further do, to these partitions, to enable read+write access?
> 
> "
> ls -l /dev/sda18
> brw-rw---- 1 root disk 259, 2 Mar 17 20:50 /dev/sda18
> bret at bret-Aspire-V3-772-UbuntuMATE:~$ sudo chmod 777 /dev/sda18

This is dangerous and you should undo it as soon as possible ("sudo
chmod 660 /dev/sda18 /dev/sda19").  Otherwise-unprivileged processes on
your system don't need the ability to write to the *device nodes*.

I suspect what you wanted to do was to modify the permissions on the
*mount points* instead.  What does "ls -ld /media/bret/Data05
/media/bret/Data06" say?

-- 
Colin Watson                                       [cjwatson at ubuntu.com]