Unable to write to new partitions

[Ralf Mardorf]

On Sat, 17 Mar 2018 18:09:49 +0100, Volker Wysk wrote:
>Am Samstag, 17. März 2018, 23:39:47 CET schrieb Bret Busby:
>> On 17/03/2018, Volker Wysk <post at volker-wysk.de> wrote:  
>> > Am Samstag, 17. März 2018, 21:34:16 CET schrieb Bret Busby:  
>> >> Hello.
>> >>
>> >> 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.  
>> >
>> > Might they be mounted read-only? What is in your /etc/fstab?
>> >  
>> 
>> None of the Dataxx partitions are displayed in running
>> cat /etc/fstab as me (user) - the Dataxx partitions are mounted by
>> selecting them using the Places -> Removable media facility.
>> 
>> Data01 to Data04 are readable and writable, being mounted this way.  
>
>Try "mount | egrep Data". This tells you the mount options of the
>mounted partitions, on the right side of the line. This should start
>with "(rw,..." or "(ro,...".
>
>
>> > Have you done a reboot after you changed your partitions? (Just
>> > guessing) 
>> 
>> I do not remember whether I had rebooted after running the chmod
>> commands on the two partitions, but, as the system crashed/froze
>> while I was trying to reload firefox before rebooting (to try to
>> avoid losing the last session, as mozilla abolished the Save session
>> functionality), I have now rebooted, after running the chmod 660
>> command as advised on both partitions, and they are sill not
>> writable.  
>
>I meant, after you changed your partition table(s).

Regarding the actuall culprit/pitfall this is completely irrelevant. No
x bit on a folder, no write access, since indexing fails.