ILIAS open source Forums

From our IT department there is a requirement, that users shall have only a limited quota for the disk space they can use.

The available amount of disk space shall be definable per user.

I wonder, how such a feature could be implemented. There is no owner concept in ILIAS. Therefore there is no way to limit the disk space to the number of file objecs that are owned by a specific person.

We could use the creator attribute of a file object. This way, each time a new file object would be created in ILIAS, we would check the disk space of all files the user has created so far, and prohibit the creation of a new file in the case this would exceed the disk quota.

If this feasible? Are there better suggestions?

Hi Werner,

how would you ensure that the creator has the permission to delete the file objects?

Regards
Alex

Good point! This can not be guaranteed.

This is an organizational problem. So, if the organization is right for this kind of quota handling, then it will work.
Requiring a specific organization ist not really a satisfactory solution.

Maybe quotas could be tied to objects then?
We could limit the available disk space in a subtree of the repository.
e.g. at a category node, course node, folder node, group node we could provide an option for the amount of disk space that it may use.
This would require disk quota handling at a lot of different objects though.

How about tying it to the "file folder" objects, that I had suggested in another thread? A file folder object could have a "max size" property.

Are there other solutions?

If an object is linked multiple times, it would be counted for every subtree. I guess that is not the desired behaviour.



This seems to be the best alternative so far. I don't know if it would be a good idea to introduce something like a file owner concept within these file folder objects only. ILIAS would store the owner of every file within the file folder objects.

This would be kind of a permission substructure that would not interfere directly with RBAC, because RBAC handles only the folder object as a whole not the files within. But RBAC could control this on a higher level, e.g. through a "Delete files of other users" permission for file folders which could be granted to the "file folder administrator".

Regards
Alex

Hi Alex,



I had some more discussions about this topic with our IT department.

There appear to be some caveats when we assign quotas to file folder resources only:
- If a user has the permission to create a file folder object, we can not prevent him from creating as many file folder objects as he wants to. Therefore the user can easily circumvent the quota.
- We can not determine which user is hogging disk space. Therefore, if overall disk usage on the server reaches a limit, we can not tell which users should remove some of their files from the system.
- We can not prevent users from using too much disk space in other resource types (mail attachments, media objects, forum attachments, ... ).


Maybe it might be better to add a transferable ownership concept to ILIAS objects?

- Each object has an attribute 'owner'.
- Ownership would be independent of access permissions. It would just be a field in table 'object_data'.
- The user who creates a specific object becomes its owner.
- Ownership of an object can be transferred from one user to another, but there can only be one user at a given time, who can own a specific object.
- Shared resources, such as file folders, fora, media pools may have a finder grained ownership mechanism. In order to prevent that a user of the shared resource can 'steal' disk space from the owner of the resource.

- Each user account has an individually configurable disk quota.
- The amount of disk space used by a user would be determined, by adding up the space used by each of the owned resources.
- Users can not create new objects, if they have exceeded their disk quota. In this case, they receive a meaningful error message, so that they can take action without needing to talk back to the system administrator.
- Users can query their disk usage.
- User administrators can query the disk usage of other users.

What do you think?

Good news

The specification for the disk quota system is now available here.

An updated specification of the disk quota system is available here.

This specification describes the current implementation in ILIAS 4.0 alpha.