Increase root disk device size Pre-4.2 Marketplace images


Prior to the 4.2 image release the default disk size of the SoftNAS OS root drive was set to 31GB on Azure and 30GB on AWS. This size has performance limitations which, in severe circumstances such as excessive 3rd party software logging to the root drive or multiple processes running with debug logging enabled, could impact user data I/O performance. With the 4.2 image release on the Platform Marketplaces the default root disk size has been increased to 100GB to take advantage of the increased performance characteristics of the larger disk size.

The root disk size cannot be reduced back to the previous default size.


This will not provide any performance boost for stable running systems.

The primary partition and root filesystem remain at the original sizes. There is no increased file system capacity added as this only applies to the underlying disk device.

Azure hosted SoftNAS Instances will require a shutdown and restart of the instance.

AWS allows for on-line expansion; the instance does not require to be restarted.


This article allows you to increase the default disk size of the SoftNAS OS root drive from 31GB on Azure and 30GB on AWS to 100GB.


Please follow the step by step guide below to increase the root disk size:



  1. Power off the SoftNAS VM

  2. Navigate to the “Virtual Machines” service and select the SoftNas VM, click on the “Disks” menu item.

  3. Click on the root disk. The name will include “OsDisk” and is listed under the OS Disk section.

  4. Enter the new size of 100GB and click save.

    Note that the IOPS limit and throughput have increased

  5. Start the VM


    1. Power off the SoftNAS VM

          az vm deallocate --resource-group <Resource Group of Instance> --name <Instance Name>

    2. Identify disk to be expanded

    a. Get the list of disks

             az disk list --resource-group JY --query '[*].{Name:name,Gb:diskSizeGb,Tier:accountType}' --output table

        b. Identify the SoftNAS VM root disk

        The root disk can be identified by the VM name and ‘_OsDisk’.

        In this case the VM name is ‘jy-cap’. The root disk to be expanded will be:


        3. Expand the disk

        az disk update --resource-group <Resource Group of VM> --name <disk name from step 2b> --size-gb 100




4.   Start the SoftNAS VM

      az vm start --resource-group (Resource Group of the VM> --name <name of SoftNAS VM>




Identify boot disk

  1. Copy the SoftNAS Instance Id.


 2. Find all Volumes associated with the SoftNAS instance in the ‘Volumes” page by searching on the SoftNAS Instance Id.
     The root disk can be identified by the attachment information. The root drive is attached as /dev/sda1


3. Increase disk size
     a.    Select the Volume identified in step 1b and select “Modify Volume” from the actions menu.


b.       Increase the ‘Size” to 100 and click ‘Modify”
          Note: The Iops value should also increase


c.      Select “Yes” to confirm.

         Note: the message includes verbiage regarding extending the OS file system. This is not supported


   1.   Get Instance ID
        aws ec2 describe-instances --filters Name=tag:Name,Values="<Instance Name>"


2. Get root Volume id

    aws ec2 describe-volumes --filters Name=attachment.instance-id,Values="<Instance_ID>" Name=attachment.device,Values="/dev/sda1


3. Expand root volume
    aws ec2 modify-volume --region <region> --volume-id <Volume_id from step 2> --size 100