## Dynamic versus static provisioning 

Storage volumes can be provisioned either manually by cluster administrator or dynamically when the PersistentVolumeClaim object is created. At the time of writing IBM Cloud Private did not support dynamic provisioning for NFS volumes, however there is an open source nfs-client-provisioner implementing this functionality, which can be installed in an IBM Cloud Private cluster. The detailed procedure is described in section “Configuring the dynamic NFS provisioner” on page 123. 

For production clusters it is highly recommended to pick the storage option that supports dynamic provisioning. 

## Snapshots and Data cloning 

Finally, do you need ability to easily snapshot and clone persistent volumes? This functionality can prove very useful for testing the applications as well as for performing backup of the data on persistent volumes. At the time of writing such functionality was available from specialized commercial storage solutions like Trident by NetApp, Portworx (with Stork), or IBM Storage Solutions for Containers. 

## System architecture heterogeneity 

IBM Cloud Private is one of the Kubernetes distributions that supports a variety of processor architectures (x86, ppc64le and s390). Some of the distributed file systems may be not available on the specific architecture that you want to use for your work. In case you plan to have heterogeneous worker nodes, we recommend that you check the latest support statement 

( https://www.ibm.com/support/knowledgecenter/en/SSBS6K_3.1.2/supported_system_conf ig/supported_os.html ). 

## 4.1.2 Maintainability requirements 

Another consideration area is about ease and cost of maintaining the storage solution. Is your organization familiar with the selected technology? Do you have a skilled personnel available to monitor, tune and troubleshoot the selected storage provider? Do you have a backup solution in place for the selected provider type? 

The answers to the above mentioned questions affect also another choice: whether to use storage provider external to the cluster or the internal one, installed directly on the IBM Cloud Private. When using the distributed file systems installed on IBM Cloud Private nodes the appropriate configuration of the provider is done automatically during the installation and will be automatically upgraded with the future releases of IBM Cloud Private. The drawback of this option is related to the additional CPU load that storage containers will introduce to your worker nodes. 

For additional backup considerations see “Backing up PersistentVolume data” on page 99. 

## 4.1.3 Windows worker node support 

With IBM Cloud Private version 3.1.2 the initial support for Windows worker nodes was introduced ( as a Technology Preview ). If any of the worker nodes in your cluster is Windows based, this affects the storage technologies that you may use for your persistent volumes. At the time of writing the Windows worker nodes provided no support for dynamic storage provisioning and the only supported volume types were: local, emptyDir and hostPath. 

