Replacing a DNode

Perform this DNode replacement procedure if you need to replace a DNode or any component of a DNode that requires powering off the DNode and removing it from the DBox chassis, such as an SSD, BMC chip, NIC, fan, PSU, or PCI switch.

Note
To request a FRU field replacement unit for a faulty component, contact VAST Support.

Note
This procedure requires a short USB A to Mini USB cable.

This replacement procedure uses the power off and replace features in VMS.

When the procedure is complete:

Passwords that were configured on the removed DNode are configured on the replacement DNode.
The chassis serial number (UID) of the DBox is applied to the replacement DNode.
Network settings are configured on the replacement DNode to match the network configuration of the removed DNode.
SSH keys are updated on the replacement DNode
The VAST OS is updated to the correct version.

Prerequisites

The peer of the DNode being replaced must be running VAST OS 12.2.2 or higher. If the peer DNode is running an older version of VAST OS, contact VAST Support.

How to Replace the DNode

Power off the DNode using one of the following methods:

From the VAST Web UI:
1. From the left menu, select Infrastructure and then DNodes.
2. On the DNodes list, identify the DNode you want to replace, click to open the Actions menu and select Power off.

From the VAST CLI:

Identify the ID of the DNode you want to replace:

vcli: admin> dnode list
+----+-----------+--------------+-------------+-----------+--------+---------+----------------------+-------------+------------+------------+-------------------+------------+----------------+
| ID | Name      | IP           | Mgmt-ip     | Host Name | State  | Enabled | Build                | DBox        | Cluster    | OS-Version | Serial            | LED Status | BMC-FW-Version |
+----+-----------+--------------+-------------+-----------+--------+---------+----------------------+-------------+------------+------------+-------------------+------------+----------------+
| 1  | dnode-112 | 172.16.3.112 | 10.61.22.21 | v168dn1   | ACTIVE | True    | release-4-1-0-479863 | dbox-JPF00D | vast168-av | 12.2.13    | 00:09:3d:07:19:35 | off        | 12.26          |
| 2  | dnode-113 | 172.16.3.113 | 10.61.22.23 | v168dn2   | FAILED | True    | release-4-1-0-479863 | dbox-JPF00D | vast168-av | 12.2.13    | 00:09:3d:07:19:49 | off        | 12.26          |
+----+-----------+--------------+-------------+-----------+--------+---------+----------------------+-------------+------------+------------+-------------------+------------+----------------+

Run the following command with the relevant ID. For example, if you are replacing the failed DNode above:
```
vcli: admin> dnode deactivate --id 2 --power-off
```

The power off option deactivates and powers off the DNode. The DNode state transitions to DEACTIVATING and then to INACTIVE.

Monitor the modify_dnode activity:
- From the VAST Web UI: Go the Activities page and check the state of the modify_dnode activity.
- From the VAST CLI: run vtask list and check the state of the modify_dnode activity.
When the state of the modify_dnode activity is COMPLETED, disconnect all QSFP28 and RJ-45 cables from the DNode.
Label the cables if needed so that you will be able to reconnect the cables to the same ports on the replacement DNode after replacement. e.g. If the QSFP28 cables are not labeled, label the left and right cables before disconnecting.
Remove the DNode. For a Mavericks DNode:
1. Move the lock bar (1) to the unlocked position (2).
2. With the lock bar unlocked, slide the DNode out (3).
Insert the replacement DNode. For a Mavericks DNode, slide in the replacement DNode and move the lock bar into the locked position.
Reconnect the RJ45 and QSFP28 cables to the equivalent ports to which they were previously connected.
Connect a USB A to mini USB cable from either of the USB A ports on the other DNode in the same DBox to the mini USB port on the replacement DNode.
When the cables are connected and the DNode state is INACTIVE, do one of the following:
- From the VAST Web UI:
  1. From the left menu, select Infrastructure and then DNodes.
  2. On the DNodes list, identify the same DNode entry again, click to open the Actions menu and select Replace.
- From the VAST CLI:
  - Run the following command with the relevant ID:
    vcli: admin> dnode activate --id ID --replace
    Note
    If any other DNode or CNode in the cluster is known to be in a non-active state, or if one of a DNode's or CNode's data network ports is disconnected from the switch, then add the additional parameter --skip-network-validation.
    That is, run this command:
    vcli: admin> dnode activate --id ID --replace --skip-network-validation
The replace process now updates the passwords, serial number, network configuration, SSH keys, and OS version.
The DNode begins to power on automatically. It transitions from INACTIVE to ACTIVATING and then to ACTIVE.
Monitor the modify_dnode activity again.
When the replacement is complete, the modify_dnode activity is reported as COMPLETED.