Manually adjust NetScaler VPX Disk Space

Contributed By: Pradeep Kumar M 

Overview

The NetScaler VPX  product is a virtual application delivery controller that can be hosted on a wide variety of virtualization and cloud platforms. Several VPX users encounter disk size constraints for various reasons including the VPX instance upgrade, necessitating a minimum of 6GB free space in the /var partition. 

This guide offers comprehensive steps to resolve this issue by expanding the disk space to meet higher capacity requirements.
Note: This is not supported for VPXs on SDX.
For SDX, Please refer : https://docs.netscaler.com/en-us/citrix-adc/current-release/deploying-vpx/deploy-vpx-faq.html#can-we-add-a-new-hard-drive-to-increase-space-on-netscaler-vpx-instance

Default Behavior 

Upon VM creation using the Netscaler build package/template, the default disk space allocated to the the VPX is 20GB. Notably, the /var partition size remains fixed at 14GB, as indicated below.

Note: Screenshots in this article are taken from the Netscaler VPX running on ESXi Hypervisor.
Note: Before changing the disk size, it is recommended to take the snapshot of the VM.

Steps to Increase the Disk space on VPX

Increase the disk size from Hypervisor or Cloud

To expand the disk size, begin by shutting down the virtual machine (VM) and then proceed to increase the current disk capacity, elevating it from 20GB to either 30GB or 40GB.  (In the case of Azure, this involves scaling from an existing 32GB to 64GB)

Jump into the boot prompt

Power on the VM and boot into the boot prompt. i.e: OK prompt or the boot prompt. This can be achieved by pressing "Ctrl + C" during boot time.

Enter single user mode

Run the following command to log into single user mode.

boot -s

Note: To enable access in the single-user mode for Azure, it's necessary to configure the com console instead of the default console. This can be done by executing the following command at the ok prompt before initiating the 'boot -s' command.

set console=“comconsole”

Setup the COM port and connect with Putty.

Verify the disk space

Check the newly allocated disk space using the following command.

gpart show

In this instance, the disk space has been expanded to 30GB, resulting in 10GB of available free space as indicated in the output of the "gpart show" command for da0.

Also, note the partition name. For this VM it is da0, but for other hypervisor or in cloud it may have different names (For example - AWS has nv0).

Resize the disk partition

The partitions can be resized by running below commands.

Resize the da0 MBR partition to include the 10GB free space by running below command.

gpart resize -i 1 da0

Incase a permission denied error is encountered while running the above command, run below mentioned command and rerun the previous resize command.

sysctl kern.geom.debugflags=16 

The partition looks like below after successfully running the commands.

Currently, it is observable that the da0 partition size has expanded to 30GB, with noticeable available free space on the da0s1 partition.

Merge the free space to the last partition

Run below command to merge the free space to the last partition on da0s1. i.e da0s1e

gpart resize -i 5 da0s1

The partition looks like below after successfully running the above command.

Now, the 10GB free space has added to 5th partition under the da0s1 partition. i.e /var

Run the below command to extend the filesystem to include newly allocated free space.

growfs /dev/ada0s1e

Now the additionally allocated 10GB is successfully added to /var.

Verify the increased disk space

Reboot the instance and verify the new disk space by running the following command in the VPX shell prompt.

df -h