7 minute read.Last Modified 2023-11-17 15:28 EST
TrueCommand-managed clusters is an experimental feature and must not be used for production or critical data management. It is intended for early testing and research purposes only.
TrueCommand 2.3 (and later), in conjunction with TrueNAS SCALE 22.12.0 (and later), can create and manage clusters, cluster volumes, and cluster volume shares.
This article describes the various screens used for clustering. If you want to create and integrate clusters, see Clustering and Sharing SCALE Volumes with TrueCommand
Clusters are an experimental feature in TrueCommand. Before using such features, please back up all your data. Do not rely on this for critical data.
The Clusters screen contains all options related to the cluster feature. To see this screen, log in to TrueCommand and click the Clusters icon in the upper left.
If you have not created a cluster, there is a single option on this screen:
|CREATE CLUSTER||Opens the form to create a new cluster.|
The cluster creation options split into two pages: Systems and Confirmation.
The initial form has two fields:
|Name||Enter a string to identify the cluster.|
|Systems||Dropdown list shows all connected TrueNAS SCALE systems available for this cluster. Clusters can consist of between 3 and 20 individual SCALE systems.|
Making selections in the Systems field adds more options.
|Delete||Clicking the delete Delete icon removes the system from the cluster.|
|Network Address||Dropdown list shows available IP addresses to use for cluster traffic. Using private dedicated network addresses is recommended.|
There is a single option on this page.
|CREATE||Begins creating the cluster, which restricts the SMB functionality on the SCALE systems.|
Successfully creating a cluster adds a cluster widget to the Clusters screen and opens options to configure the new cluster. These options are split into four screens: VIPs, Associate VIPs, Active Directory, and Confirmation.
The VIPs page has options and fields added for each SCALE system in the cluster.
|ADD||Adds another line under VIPs for IPs and netmasks.|
|Address||Virtual IP address for one of the cluster systems.|
|Netmask||Netmask for the IP address.|
The Associate VIPs page allows you to select interfaces to assign to the VIPs.
|Interface||Select an interface from the dropdown list of interface options and assign it to the VIP.|
The options on this page let you establish a connection between an Active Directory environment, SCALE systems, and TrueCommand.
|Domain Name||Enter a string for the Microsoft Active Directory (AD) environment host name.|
|NetBIOS||Automatically populates with the cluster name.|
|Username||Enter a string for the account credential to establish the AD connection. You must use an account with administrative access.|
|Password||Enter a string for the account credential to establish the AD connection. You must use an account with administrative access.|
All chosen settings display here for you to confirm before being applied to the cluster.
|CONFIRM||Saves the configuration settings and permanently apply them to the cluster.|
Clusters display as standalone cards.
The card displays the name of the cluster, the current state, and the names of the systems used in the cluster (Nodes). Click the more_vert Options icon to see management options for the cluster. Click the ^ or v icons to minimize or expand (respectively) the list of nodes.
|CREATE VOLUME||Opens the form to create new clustered storage.|
|Rename||Opens the form to enter a new Cluster Name.|
|Delete||Disconnects each SCALE system from the cluster and removes the card from TrueCommand. Shows a confirmation popup when clicked.|
Clicking CREATE VOLUME for an existing cluster shows options to configure new clustered storage. The options split into two pages: Details and Confirmation.
|Name||Enter a string as an identifying label for this cluster volume.|
|Type||Dropdown list. Select the layout and behavior for the volume.|
|Cluster||String (disabled). Shows the cluster that controls the new volume.|
|Brick Size||Enter an integer and select from the dropdown list to define storage capacity. Allows numeric values and selecting units of size.|
|Pools||Dropdown list. Select a storage pool on the individual SCALE system that provides capacity for the cluster volume.|
The Type field has four options:
Replicated volumes are the most similar to ZFS mirrors. They have exact copies of all data on all bricks. Since TrueNAS SCALE SMB cluster implementation requires a minimum of three nodes, a replicated volume has three identical copies of all data.
A replicated volume can experience multiple brick failures, yet you can still access the data if a single brick is still accessible. Replicated volumes excel in data reliability and data redundancy at the cost of lower overall storage.
Distributed replicated volumes distribute files across replicated sets of bricks. You set the replica count during the initial volume configuration.
Distributed replicated volumes require a minimum of three replicas to avoid potential issues with split-brain. The number of bricks must be a multiple of the replica count. The minimum number of nodes for this volume type is six since each replica set requires three nodes.
Distributed replicated volumes are best when you need highly-available data with redundancy protection, although they scale poorly.
TrueCommand currently allows distributed replicated volumes with two replicas. This unintended behavior can lead to potential data loss due to split-brain situations. We are working to resolve this in TC-2626.
Dispersed volumes are most similar to RAIDZ. Data is striped across the bricks with parity added. You configure the number of redundant bricks during volume creation. The number of parity bricks determines the number of bricks the cluster can lose without impacting volume operation.
The Confirmation page shows details for the chosen volume Type and storage makeup of the new clustered volume.
|BACK||Click the button to go to the previous configuration page.|
|CREATE||Click the button to save the configuration and build the clustered volume on each system in the cluster.|
Created cluster volumes display in the related cluster card.
The card displays the name, used storage, and volume status. Click the volume name to expand the details and see more management options.
|DELETE||Click the button to remove the volume from the cluster and destroy stored data.|
|CREATE SHARE||Opens the form to configure a new SMB share for remote access to this cluster volume.|
Adding a cluster share shows a few options.
|Cluster||String (disabled). Shows the name of the cluster related to this share.|
|Cluster Volume||String (disabled). Shows the name of the cluster volume to share.|
|Name||Enter a string to create a label for this new cluster share.|
|ACL||Dropdown list. Access Control List. Choose permissions for the share.|
|Readonly||Checkbox disables or allows file management options for connected users. Select to disable.|
|CONFIRM||Click the button to save the settings, create the share, and make the cluster volume accessible to Active Directory user accounts.|
- POSIX_OPEN - Grants read, write, and execute permissions to all users.
- POSIX_RESTRICTED - Grants read, write, and execute to owner and group, but not others. The template may optionally include the special-purpose ‘builtin_users’ and ‘builtin_administrators’ groups and Domain Users and Domain Admins groups in Active Directory environments.
Click the cluster volume name to open the Cluster Volume Details and see any shares.