Photo by CHUTTERSNAP on Unsplash
Persistent storage management for Kubernetes
Data Logistics
With ongoing developments in container technology in the area of data management and persistent storage, business-critical applications have been running in cloud-native environments with containers orchestrated by Kubernetes. A container is just a software box without its own operating system. Originally, a container would not only contain the app or microservice, but also all the necessary drivers, dependencies, and data the respective application needed to run. If the container was deleted, all that was gone, which meant that a data store was needed that would stay alive regardless of the existence of a container or its pod.
PVs, PVCs, and Storage Classes
Two variants are available: persistent volumes (PVs) and persistent volume calls (PVCs). PVs are static and defined by the admin in advance, belong to a Kubernetes cluster, and perish with it, but survive the deletion of individual containers. The admin assigns all their characteristic properties: size, storage class, paths, IP addresses, users, identifiers, and the plugin to be used.
Storage classes have certain characteristics such as quality of service (QoS), replication, compression, backup, and more, which the container storage interface (CSI), but not Kubernetes itself, supports. PVs now have many different storage classes in Kubernetes clusters, from local storage to storage attached with Network File System (NFS), iSCSI, or fibre channel to block storage from Azure, AWS, or Google. All PVs of a storage class are accessible through the same API or are coupled to the pod.
PVCs, on the other hand, are requested by the application manager as a storage class according to the application requirements. Depending on the request, a PVC is created from the template of the corresponding storage class and is attached to the pod from that point on (i.e., it also goes down with the pod). A stateful set means that PVCs can be copied
...
Buy this article as PDF
(incl. VAT)
Buy ADMIN Magazine
US / Canada
UK / Australia
Related content
-
Cloud-native storage for Kubernetes with Rook
Kubernetes is known to be inflexible when it comes to persistent storage, but Rook now offers cloud-native storage and seeks to achieve harmony. -
Optimally combine Kubernetes and Ceph with Rook
Ceph distributed storage and Kubernetes container orchestration come together with Rook. -
Kubernetes containers, fleet management, and applications
Kubernetes is all the rage, but many admins find themselves struggling to get started. We present the basic architecture and the most important components and terms. -
Cloud-native storage with OpenEBS
Software from the open source OpenEBS project provides a cloud-native storage environment that makes block devices available to individual nodes in the Kubernetes cluster. -
Production-ready mini-Kubernetes installations
Kubernetes can be highly complex, with massive setup routines that are totally over the top for newcomers. If you want to try out Kubernetes or run it in production, you have a number of options, even if you decide not to use the comprehensive packages from established vendors.