The LDAP User Management can be opened from the main menu Components  LDAP  User Management. It shows a list of all LDAP Users on the left side and information about the currently selected user on the right.

Click the New button to create a new user. The right side of the window then allows to input the necessary data for creation. Some fields are pre-set with default values. The label before each field indicates if the input is valid: It will be green if the current value is acceptable, yellow if it’s possible to complete it to an acceptable value and red for invalid input. The first field to be filled is the User Name. Changing it will also change the Home Directory field. The latter is pre-set using the Homedir Prefix with the username appended. Once all fields are green, the Create button will also turn green, indicating that it can be clicked to create the new user.

Once a new user has been created, its random initial password is shown in a popup window. The user will then appear in LDAP immediately and be usable on any node with the standard Qlustar Nameservice config. However, this is not the default setting for a node to avoid overloading the LDAP server with simultaneous requests from many compute nodes on large clusters. The default setup is to create a passwd and group file from the LDAP data which are sent to nodes during the early boot process. This way user/group data are accessible via local lookups leaving the server mostly idle. Click the Sync now button in the popup to update the passwd and group file on any node using the default synchronization method.

The user information has 2 optional parts.

The information for an existing user can be edited by first selecting the user on the left side and then modifying the relevant field. The label is color-coded again to show the validity of the input. The Save button must be clicked to save the changes. To undo them without saving, just select a different user or close the window.

A user can be added to or removed from a group by opening the context-menu in the Groups box. Selecting an entry will add or remove the user from the corresponding group. A user’s password can be reset by selecting the user on the left side and clicking the Reset Password button. A window with the new password will then come up.

Once the cluster has many users, it can become hard to find a particular one in the user list. To simplify this, the list can be filtered as follows: Select one of the available filters from the Filter drop-down menu and enter a regular expression in the text field next to it. The user list then updates as you type, showing only users that match the regular expression for the selected filter.

To delete users, select them on the left and click the Delete button.

The LDAP Group Management dialog can be opened from the main menu Components  LDAP  Group Management.

It allows creation and removal of groups as well as the management of group membership. The corresponding window is split into three parts: The left part shows a list of all LDAP groups, the middle displays details for the selected group, including a list of its members and the right has a list of users.

The list of groups can be sorted by either the group ID or the group name in ascending or descending order by clicking on the column name. It can also be filtered by specifying a regular expression for the group name in the Filter text field at the bottom. Groups can be removed in batches by selecting them in the list and clicking the Remove button.

Selecting a group on the left will display its details in the middle: At the top the group name and group ID and the description of the group underneath. At the bottom is the list of users that are members of the group. Users that have this group as their primary group are shown in bold. The context menu for the Members box allows modifying the membership of the selected users in four ways:

If a group is selected with its details shown in the middle, the right side lists users that are not members of the group. This list supports filtering to simplify finding users, just like in the LDAP User Management.

Selected users in this list can be added to the group shown in the middle by dragging them into the Members box. This also works in the other direction: Selecting users in the Members box and dragging them into the All Users box will remove them from the group, but only if this group is not their primary group.

A new LDAP group can be created by clicking the New button. A group name must then be entered. The group ID can be changed from the suggested one and a description for the group can be added in the box below the name. The labels are color-coded to show valid inputs: Green for valid inputs, yellow for partial ones and red when the group ID is already in use. If all inputs are valid, the Create button will turn green and clicking it will create the new group.

The description of the group can be edited by clicking in its box. When it is changed, the Undo and Save buttons become active. Click the Save button to save it.

The currently displayed group can be deleted by clicking the Remove button. Multiple groups can be selected and removed in batches.

Two methods for importing users are supported: a) Import of users, passwords and groups from flat files in the standard UNIX formats. b) QluMan may be configured to allow for a single sign-on setup where users can be imported from and authenticated against an Active Directory (AD) server. In such a setup, the Qlustar LDAP server uses SASL pass-through authentification against AD passwords instead of storing password hashes.

The LDAP Configuration dialog can be opened from the main menu Components  LDAP  Config. It handles a few settings relevant to the user and group management in qluman-qt.

In QluMan, the user ID for LDAP users is limited to a customizable range of IDs. By convention, user IDs below 1000 (200 for CentOS) are reserved for system accounts and daemons. Per default, QluMan uses 2000 as the minimum value for UIDs. On the other hand, there is no well-defined convention for the maximum.

In some situations, it is convenient to assign certain ranges of IDs to certain user groups. Changing the Min and Max values before user creation then helps by making qluman-qt suggest UIDs only within that range for new users.

The Next value for User ID is the UID qluman-qt will suggest the next time a user is created. Once created, the Next value is incremented to the next unused UID. When it hits the Max User ID, it will be reset to Min User ID and start all over. The reason to explicitly keep track of this instead of always using the smallest free UID is to avoid reusing UIDs of deleted users. If a UID is reused, there is always a risk of loosing data protection: Left-over files on the system belonging to the old user would be accessible by the new user. The same mechanism is implemented for the Min, Next and Max settings of Group ID.

The Default Group, Default Mode and Homedir Prefix can also be set here. They are used to fill the corresponding fields with default values when creating a new user. The homedir is constructed from the Homedir Prefix and the username of the new user.

Finally, a list of cluster nodes can be entered to set Homedir Hosts. The default setting is just beosrv-c, the head-node. A change is only needed if the home directories cannot be created on the head-node. This can be the case if home directories are on an external NFS server or a Lustre filesystem for example. If a list of hosts is entered here, they will be checked for accessibility one by one and the home directory created on the first one accessible.

A hostlist can either be entered directly or hosts can be selected in the Enclosure View and the Selected Hosts button be clicked to enter a hostlist of the selected hosts.