https://askubuntu.com/questions/542328/send-ctrlaltf1-crtlaltf7-into-virtualbox

1. Login to the Sage notebook – Username: admin, Password: sage

2. Login to the sage account in the virtual machine – Username: sage, Password: sage

3. Login as root (administrator account) to the virtual machine – Username: root, Password: sage

Source: SageAppliance/Sage-5-x-or-6-x – Sage Wiki

h1:not(.site-title)::before, h2::before{
display:none;
}

Source: Removing Short Line Above Headings in Twenty Nineteen | WordPress.org

Enable HTTP Strict Transport Security¶

While redirecting all traffic to HTTPS is good, it may not completely prevent man-in-the-middle attacks. Thus administrators are encouraged to set the HTTP Strict Transport Security header, which instructs browsers to not allow any connection to the ownCloud instance using HTTP, and it attempts to prevent site visitors from bypassing invalid certificate warnings.

This can be achieved by setting the following settings within the Apache VirtualHost file containing the <VirtualHost *:443> entry:

<IfModule mod_headers.c>
  Header always set Strict-Transport-Security "max-age=15552000; includeSubDomains"
</IfModule>

Source: Hardening and Security Guidance — ownCloud 9.1 Server Administration Manual 9.1 documentation

opera://net-internals/#hsts

Source: Opera Forcing HTTPS | Opera forums

Manually disable locking state:

• put ownCloud in maintenance mode: edit config/config.php and change this line:
  'maintenance' => true,
• Empty table oc_file_locks: Use tools such as phpmyadmin or connect directly to your database and run:
  DELETE FROM oc_file_locks WHERE 1
• disable maintenance mode (undo first step).

Source: File is locked – how to unlock – FAQ – ownCloud Central

https://unix.stackexchange.com/questions/52667/file-permission-issues-with-shared-folders-under-virtual-box-ubuntu-guest-wind

https://forum.owncloud.org/viewtopic.php?t=32469

https://stackoverflow.com/questions/26740113/virtualbox-shared-folder-permissions

https://askubuntu.com/questions/136788/how-do-i-list-the-members-of-a-group

OwnCloud /media/sf_OwnCloud  vboxsf  rw,uid=33,gid=33    0   0

Source: [Solved]Permissions Problem with Shared Folder in Virtualbox – ownCloud Forums

'files_external_allow_create_new_local' => 'true',

Source: Local :: ownCloud Documentation