Unable to write to new poartitions

[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.

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
bret at bret-Aspire-V3-772-UbuntuMATE:~$ ls -l /dev/sda18
brwxrwxrwx 1 root disk 259, 2 Mar 17 20:50 /dev/sda18
bret at bret-Aspire-V3-772-UbuntuMATE:~$ df -h /dev/sda18
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda18       77G   52M   73G   1% /media/bret/Data05
bret at bret-Aspire-V3-772-UbuntuMATE:~$ sudo chmod 777 /dev/sda19
bret at bret-Aspire-V3-772-UbuntuMATE:~$ ls -l /dev/sda19
brwxrwxrwx 1 root disk 259, 3 Mar 17 20:50 /dev/sda19
bret at bret-Aspire-V3-772-UbuntuMATE:~$ df -h /dev/sda19
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda19       73G   52M   69G   1% /media/bret/Data06
"

Thank you in anticipation.

-- 
Bret Busby
Armadale
West Australia
..............

"So once you do know what the question actually is,
 you'll know what the answer means."
- Deep Thought,
 Chapter 28 of Book 1 of
 "The Hitchhiker's Guide to the Galaxy:
 A Trilogy In Four Parts",
 written by Douglas Adams,
 published by Pan Books, 1992

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