shared folder are the key functionality in openmediavault around which all services revolve. They will be created as subvolumes on BTRFS file systems or simple directories on all other file systems supported by openmediavault. If a shared folder is located on a BTRFS file system, then it is possible to create snapshots of it. This can be done manually or via scheduled tasks.
When a shared folder is created using the add button, the window form displays the following options:
- Name: The logical name. This can override the path name. Typing a name here will fill the path with the same string.
- Device: The parent filesystem associated with the shared folder.
- Path: The relative path to the mounted device. To share the whole disk just type
- Permissions: The default descriptive text will create the shared folder with
Logical name Octal mode Administrator: read/write, Users: no access, Others: no access 700 Administrator: read/write, Users: read only, Others: no access 750 Administrator: read/write, Users: read/write, Everyone: no access 770 Administrator: read/write, Users: read only, Everyone: read-only 755 Administrator: read/write, Users: read/write, Everyone: read-only 775 (Default) Everyone: read/write 777
This is how a shared folder looks inside the
<sharedfolder> <uuid>9535a292-11e2-4528-8ae2-e1be17cf1fde</uuid> <name>videos</name> <comment></comment> <mntentref>4adf0892-cf63-466f-a5aa-80a152b8dea6</mntentref> <reldirpath>data/videos/</reldirpath> <privileges> <privilege> <type>user</type> <name>john</name> <perms>7</perms> </privilege> <privilege> <type>user</type> <name>mike</name> <perms>5</perms> </privilege> </privileges> </sharedfolder>
Some of the elements explained:
- uuid: Internal database reference number.
- name: logical name given to the shared folder.
- mntent: the associated filesystem reference. The number is in the
uuidformat, the fstab section in
config.xmlshould contain a
<mntent>reference with this number.
- reldirpath: Path relative to the parent filesystem.
- privileges: Users associated with the shared folder and their access level.
When a plugin or a service uses a shared folder it stores the uuid value only. Later on
using helper scripts or internal openmediavault functions the full path can be obtained
just by using the
uuid. An example in shell:
$ . /usr/share/openmediavault/scripts/helper-functions && omv_get_sharedfolder_path 9535a292-11e2-4528-8ae2-e1be17cf1fde
More information about helper functions.
A shared folder can be used across all over the system backend. Is available to select it in sharing services (FTP, Samba, RSync, etc.) at the same time. Plugins can use them also just by using the shared folder combo class.
- A shared folder belongs to an internal openmediavault database filesystem entry. Is not possible to unmount the filesystem without deleting the folder configuration from the web interface.
- If a shared folder is being used by a service (FTP, plugins, etc.) is not possible to delete it. Is necessary to disengage the shared folder from the service(s) or section(s) that is holding it before proceeding with removal. This will also prevent to unmount a device from the web interface in the filesystem section if there is still a shared folder associated with it.
- Due to the design of the software is not possible at the moment to know what section or service is holding which shared folder.
Edit shared folder is possible, but it has some limitations. You can only change the parent device volume. Once the parent device is changed the backend will reconfigure every service that is using a shared folder and stop/start daemons accordingly.
Be aware that changing the parent device volume will not move the data from one filesystem to another.
NFS Server: Editing the parent device will not descent into
/etc/fstab. Make sure you edit the share in the NFS section so the bind can be remounted.
Same as in the user section, the window here is relative to the shared folder. It will display for the selected shared folder all the openmediavault users/groups and their corresponding privileges.
As you can see from the code block in the add section privileges are expressed in the internal database in the same manner as permissions in Linux, simplified using the octal mode: read/write(7), read-only(5) and no access(0).
If a privilege is changed, it means a change in the shared folder database section. This database event will trigger a reconfiguration of SMB, FTP and AFP, it will also restart all the above daemons. A plugin using shared folder, but not the privilege information from the database entry should not get reconfigured/restarted if a change occurs just in privileges.
ACL (Access Control List)¶
Provides fine grained permission control besides the standard POSIX permissions. The usage of ACL is not recommended for the average home user. If a server is using an extensive list of users then ACL could suit better  .
The expanded ACL window displays three panels. Left one is a browser of the selected shared folder, so you can see the apply ACL to the current folder or a subdirectory and so on.
The left panel displays all current openmediavault users and system accounts and their current ACL of the selected folder. This panel actually reads ACL from the selected folder.
The bottom panel displays the standard POSIX permission of the selected folder or subfolders in a user friendly interface.
If you want just to reset linux permissions, just use the recursive checkbox and change options only in the bottom panel, and not selecting any ACL user/group in left panel.
- openmediavault mounts all Linux filesystems with ACL enabled. Only native linux POSIX filesystems support ACL. The button gets disabled for HFS+, NTFS, FAT, etc.
- ZFS provides ACL support, just need to enable the pool/dataset property.