I'm still learning, so please bear with me.
I installed Apache, php, and mysql and have some vhosts running, used certbot to secure the domains and all is well there. I can access the domain, run scripts, etc.
I also have an internal RAID 1 array that is formatted to ext4 and is mounted to /media/mcp/Vault
using the following entry in fstab:
/dev/disk/by-uuid/e80c874e-b7cf-4cd0-ab00-1b1a43b88516 /media/mcp/Vault auto nosuid,nodev,nofail,x-gvfs-show 0 0
The script in question lives in /var/www/domain.com/testwrite.php
and contains nothing but the following code:
<?php
$dir = '/media/mcp/Vault';
$files = scandir($dir);
print_r($files);
/media/
is owned byroot:root
and has permissions of0755
./media/mcp/
is owned byroot:root
and has permissions of0750
/media/mcp/Vault/
is owned bywww-data:www-data
and has permissions of0777
Yet when I run that script, I get the following error:
Warning: scandir(/media/mcp/Vault): failed to open dir: Permission denied in /var/www/domain.com/testwrite.php on line 8
Warning: scandir(): (errno 13): Permission denied in /var/www/domain.com/testwrite.php on line 8
Line 8 is $files = scandir($dir);
of course.
Edit:
I added the following to /etc/apache/apache.conf
as per the linked question:
<Directory /media/mcp/Vault/>
Options Indexes FollowSymLinks
AllowOverride None
Require all granted
</Directory>
... and restarted apache, but there was no change; I still get the same errors.
Then I changed /mcp/
to 0755 and - I think - the combination of those two changed resolved my issue.