Expand your storage pool size

As your cluster usage increases and the data on your storage pools grows, you may start to run out of capacity. In order to correct this, you must determine the best way to expand your storage pool size.

You can expand your storage pools horizontally by adding drives or vertically by increasing the size of the drives you have. Which method you choose depends on the following factors:

  • How many drives your pool contains already
  • How large the drives in your pool currently are
  • The difficulty or cost associated with each method
  • The environment you’re operating in: cloud or on-prem

If you’re operating on the cloud, you may choose to expand your pools to avoid potentially disruptive restriping operations associated with adding drives. If you’re operating on-premises, you may not be able to increase the size of your disks if you don’t have any remaining physical capacity.

Once you’ve considered your options and chosen the best approach for your cluster, you’re ready to perform the resizing operation.

NOTE: Pool expansion of pools with repl1 volumes is not supported in the following scenarios:

  • The pool also has auto journal devices
  • The add-disk operation is used to expand the pool size
  • The pool is on the Azure cloud

Expand a pool automatically on the cloud

If you’re running on the cloud, factor automation into your decision for which pool resize approach you use. The pxctl service pool expand command allows you to perform resize operations without manually adding new drives or increasing drive capacity on your cluster.

When you enter the pxctl service pool expand command, Portworx uses your cloud provider’s API to create new drives and attach them or to expand the existing drives with no further input from you.

You can control the pool expand operation by specifying which operation you want to use: resize-disk or add-disk, or you can specify auto to let Portworx determine the best way to resize your storage pools based on your cloud provider.

By default, each pool can have a maximum of 6 drives. If required, you can use the runtime option limit_drives_per_pool to change this value.

The following table shows the maximum number of drives (which includes boot drives, Portworx cloud drives, and any other drives) for various platforms:

Platform Maximum number of drives
AWS, Azure, GCP, and IBM 8
vSphere 12
Pure FlashArray 32


You must be running Portworx on one of the following cloud providers:

  • AWS
  • Azure
  • GCP
  • IBM VPC Gen2 Platform (Portworx 2.11.0 or newer)

NOTE: For IBM, you must have the IBM Block CSI driver version 4.4 or newer. To check your version, run the following command:

ibmcloud ks cluster addon ls --cluster <cluster-id>

If you need to update the IBM CSI driver on your cluster, perform the following steps:

  1. Remove the currrent version using the following command:

    ibmcloud ks cluster addon disable vpc-block-csi-driver --cluster <cluster-id>
  2. Enable cluster addon with --version 4.4:

    ibmcloud ks cluster addon enable vpc-block-csi-driver --cluster <cluster-id> --version 4.4
  3. Check that the correct version is present:

    ibmcloud ks cluster addon ls --cluster <cluster-id>
    Name Version Health State Health Status
    vpc-block-csi-driver 4.4* (4.3 default) - Enabling

Expand a cloud-based pool automatically

Expand a cloud-based pool by entering the pxctl service pool expand command with the following options:

  • The --operation option with the operation you wish to perform
  • The --size option with the minimum new size of the pool in GiB
  • The --uid option with the ID of the pool you wish to resize

    pxctl service pool expand --operation auto --size 1000 --uid <pool-UUID>

For example:

pxctl service pool expand --operation auto --size 1000 --uid 46f7e68b-3892-4ddd-88fc-aef346e61d89

Run the following command to find the UUID for a pool:

pxctl service pool show


PX drive configuration:
Pool ID: 0
        UUID:  46f7e68b-3892-4ddd-88fc-aef346e61d89
        IO Priority:  HIGH
        Labels:  iopriority=HIGH,medium=STORAGE_MEDIUM_SSD
        Size: 384 GiB
        Status: Online
        Has metadata:  Yes
        Balanced:  Yes
        1: /dev/sde, Total size 128 GiB, Online
        2: /dev/sdf, Total size 128 GiB, Online
        3: /dev/sdg, Total size 128 GiB, Online
        Cache Drives:
        No Cache drives found in this pool
Journal Device:
        1: /dev/sdc1, STORAGE_MEDIUM_SSD

Expand a pool manually

If you’re running Portworx on-prem or want to resize a pool manually using a certain drive, you must use different pxctl service commands.

Add drives

You can add more capacity to your storage pools by adding drives to them. When you add drives to your node, Portworx determines what pool to add them to by comparing the drive properties with those of the pool. Ensure that the drives you add are as closely related to the pool in size, type, and performance as possible.

  1. Identify a storage pool that’s running low on capacity
  2. Add drives to your node similar in kind to the drives comprising the pool you need to expand
  3. Add the drive by entering the pxctl service drive add command, specifying the following:

    • The --drive flag and the name of the drive you want to add
    • The --operation start flag

      pxctl sv drive add --drive /dev/sde --operation start
      Adding drives may make storage offline for the duration of the operation.
      Are you sure you want to proceed ? (Y/N): y
      Drive add done: Storage rebalance is in progress

    Once you’ve added the drive, Portworx begins restriping the pool to include the new drive.

  4. Monitor the drive add operation status by entering the pxctl service drive add command, specifying the following:

    • The --drive flag and the name of the drive you added
    • The --operation status flag

      pxctl service drive add --drive /dev/sde --operation status

    When the status shows as Drive /dev/sde already in use by PX., storage will be brought online automatically when this operation completes.

Expand a pool to consume all drive capacity

If you can create extra capacity on your drives, you can expand a pool to consume all of its available capacity.

  1. Identify a storage pool that’s in need of expansion
  2. Resize your drive and drive partition, if required
  3. On the node containing your target drive, enter the pxctl service pool update command, specifying the --resize option and the ID of the pool you want to resize:

    pxctl service pool update --resize 4
    Pool properties updated

Last edited: Tuesday, May 9, 2023