To configure a new data disk in the cluster, take the following steps:

Step 1: Adding a new disk to the node

Once the disk is attached to the node, format it and mount it to some location.

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Note:

The following steps assume that you have mounted the new disk in the /datadisk1 location.

sudo -i
DATADISK_MOUNT="/datadisk1"
DATA_DISK_DEV="/dev/$(tree /dev/disk/azure | grep -w "\slun0\s" | awk -F/ '{print $NF}')"
# if this fails try to hardcode the data disk that you see attached when using command lsblk 
# example: DATA_DISK_DEV="/dev/sdc"
echo "Partitioning ${DATA_DISK_DEV}, creating partition \"data\" with 100%"
parted "${DATA_DISK_DEV}" --script mklabel gpt mkpart "data" ext4 0% 100%
while [[ ! "$(blkid -o device | grep -e "^${DATA_DISK_DEV}1$")" ]]; do
  echo "Waiting for ${DATA_DISK_DEV}1 to be available"
  sleep 5;
done
echo "Creating ext4 FS for ${DATA_DISK_DEV}1"
mkfs.ext4 "${DATA_DISK_DEV}1"
partprobe "${DATA_DISK_DEV}1"
mkdir "${DATADISK_MOUNT}"
mount "${DATA_DISK_DEV}1" "${DATADISK_MOUNT}"
UUID=$(blkid -o value -s UUID "${DATA_DISK_DEV}1")
grep -q "${DATADISK_MOUNT}" /etc/fstab || 
printf "# data-disk\nUUID=%s    %s    ext4    defaults    0    0\n" "${UUID}" "${DATADISK_MOUNT}" >> /etc/fstab
exit

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Note:

In multi-node HA-ready production installations, it is recommended to attach additional disks to all the server nodes. There is no need to attach additional disks to agent nodes.

Step 2: Getting the password for the Rancher server

Perform the following steps from one of your server nodes:

1. Ensure that you are a root user.

sudo su -

2. Ensure that you have set the right environment variables.

export KUBECONFIG=/etc/rancher/rke2/rke2.yaml
export PATH=$PATH:/var/lib/rancher/rke2/bin

3. Run the following commands to get the server password.

kubectl get secrets rancher-admin-password -n cattle-system \ 
  -o jsonpath={.data.password} | echo $(base64 -d)

Step 3: Login to the Rancher server

1. Navigate to the Rancher server by entering monitoring.fqdn in your browser's address bar.

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Note:

If your cluster FQDN is automationsuite.mycompany.com, then rancher server URL is monitoring.automationsuite.mycompany.com.

2. Use the following credentials:

• Username: admin
• Password: retrieved in Step 2.

Step 4: Navigate to Longhorn nodes configuration

1. Click the Explorer button as shown in the following image.

2. Click Cluster Explorer in the top-left corner, and then select Longhorn as shown in the following image.

3. Select Longhorn on the Overview page.

4. On a Longhorn dashboard, select Node in the top navigation bar.

Step 5: Open Edit Node and Disk configuration dialog

1. Select the node and click the Edit Node and disks button.

Step 6: Add a new disk in the cluster

1. Click the Add Disk button.

2. Provide the following details:

• Path: Path where you have mounted additional datadisk in Step 1. If you are mounting new disk at location /datadisk1, then use this location

• Storage Reserved: 0 Gi

• Scheduling: Enabled

3. Once you have filled in the required information, click the Save button.

Step 7: Verify the disk is configured in the cluster

1. Once the disk is configured in cluster, you can see a Ready and Schedulable status next to it, as shown in the following image:

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Important!

In multi-node HA-ready production installations, you have to perform Step 5, Step 6, and Step 7 for all the server nodes on which you attached new disks.